小数除法及简算

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第一章 小数除法

第一章 小数除法

第一章小数除法培优选讲类型一计算篇知识精讲:小数的计算技巧是指小数的简算与巧算.它除了可以运用整数四则运算的简算与巧算的方法之外,还可以运用小数的性质及运算的性质进行简算与巧算.1.运用加法交换律、结合律进行简算:在进行几个数相加的运算时,可以把其中的两个或几个数相加能凑成整数的先进行运算,可以使计算简便.2.在加减混合运算中,如果小数接近整数时,可将小数拆成整数与纯小数,然后再分别进行整数与纯小数的计算.3.运用去括号、添括号的方法进行简算:a.在加减混合运算中,如果去括号或添括号可使运算简便的话,可采用去括号或添括号的方法.如果括号前面是“加号”,则去括号时,括号里的运算符号不变;如果括号前面是“减号”,则去括号时,括号里的运算符号都要改变:即“+”变“-”,“-”变“+”.添括号法则类似.b.在乘除混合运算中,用去括号或添括号的方法进行简算时,如果括号前是“乘号”,去掉括号时,括号内的运算符号不变;如果括号前是“除号”,去掉括号时,括号内的运算符号改变;即“×”变“÷”,“÷”变“×”.添括号法则类似.4.运用乘法交换律、结合律进行简算:在进行几个数相乘时,可以把其中两个或几个数相乘能凑成整数的先进行运算,可以使运算简便.5.运用乘法分配律进行简算.6.运用积、商的变化规律进行简算.a.根据商不变性质进行简算b.根据积的变化规律进行简算例题精讲:一.加减法巧算(凑整):例1.巧算(1)7.973 1.275 1.473 2.225+-+(2)325.24425.24625.24925.24525.24++++.(3)1.9 1.99 1.999199.9919999.91999999+++++二.小数乘除法凑整例2.计算:1.250.268⨯⨯12.345.678.9 4.115.78228⨯÷⨯⨯÷()三.提取公因数例3.计算3.70.56 3.70.44⨯+⨯=:3790.000381590.00621 3.790.121⨯+⨯+⨯23.40.6523.30.35⨯+⨯1.2332.3133.123_____÷+÷+÷=四.小数的扩缩倍例4五.小数数列计算例5.计算:+++++++0.10.30.50.70.90.110.99+--++--+++--.10.990.980.970.960.950.940.930.040.030.020.01()() ++++++++-+++++++0.10.30.50.70.90.110.130.990.20.40.60.80.100.120.98六.换元法例6.计算:()()()() +++⨯+++-++++⨯++1 1.2 1.23 1.234 1.2 1.23 1.234 1.23451 1.2 1.23 1.234 1.2345 1.2 1.23 1.234七.解方程例7.课堂练习:练习1.计算(1)1.3434.1 2.56++ (2)3.177.48 2.380.53 3.48 1.62 5.3+-+--+练习2.2.515640.125⨯⨯⨯ 4.5 4.80.25150.24⨯÷÷÷.练习3.1.25 3.141250.025712500.00229_______⨯+⨯+⨯=75 4.6717.9 2.5⨯+⨯=练习4.练习5.计算:1234567820132014201520162017 --++--+++--++练习6.计算:20092009200920082009201020092007⨯-⨯()()()() 10.360.450.360.450.540.360.4510.360.450.54++⨯++-+⨯+++练习7.解方程:作业:1.计算:(1)9.99629.98169.93999.5+++ (2)89899899989999899999++++2.计算:7.5×9.6÷0.25÷0.32 3计算:6.4 1.250.25⨯⨯4.巧算(1)4.57 4.5 6.94⨯-⨯ (2)1.117.6 3.30.8⨯+⨯(3)(4)5211.1 2.6778________⨯+⨯=5.李老师在黑板上写了四个算式:①74690.7÷;②7.4690.007÷;③0.74690.07÷;④746.97÷.请把它们按照商从小到大的顺序排列起来______<________<________<_________.6.计算:0.03593530.0350.07610.5⨯+⨯+⨯⨯=7.8.计算:0.79.799.7999999999.7++++.+--++--+++-9.计算:10310210110099989796321=++⨯++-+++⨯+ 10.计算:(10.230.34)(0.230.340.45)(10.230.340.45)(0.230.34)11.类型二应用篇一.和差倍解决小数点移动问题例1.(1)乐乐与小小一共有896.5圆,将乐乐的钱数的小数点向左移动一位,他的钱数就和小小一样多,请问两人各有多少钱?(2)一个小数,把小数点向右移动一位,所得的数比原来增加了69.84,这个小数原来是多少?二消去法解题例2.(1)阳光小学上午买了4个足球和2个篮球,共付436.8元,下午又买了同样的1个足球和2个篮球,共付237元。

(完整)小数除法脱式运算+简算260道含答案,推荐文档

(完整)小数除法脱式运算+简算260道含答案,推荐文档

小数除法脱式运算+简算260道一.计算题(共50小题)1.用你喜欢的方法计算.32×12.5×0.25 6.1×4.2+5.8×6.1 1.7÷2.5÷0.416.1﹣4.2﹣5.8.3.脱式计算4.8÷(1.2÷0.5)12.8﹣12.8÷571.4÷(7×6)4.用你喜欢的方法计算0.65×101﹣0.65 12.6﹣3.25+6.756.35÷0.2÷0.5 5.7×1.2÷19 1.25×3.63×0.8.5.我能用喜欢的方法计算下面各题.0.11×1.8+8.2×0.11 3.5﹣3.5×0.980.75×18÷0.150.25×4.78×8.6.能简算的要简算.17.3÷0.125÷8 14.72×0.7+5.28×0.73.5÷0.56 8.5×9.9+0.82.7.递等式计算,有简便运算的用简便方法38.75﹣(24.5+8.75)0.4×2.32×0.250.75×101 4.2﹣3.2×0.97.56×99+7.5670.3﹣17.48÷7.6 3.64÷5.2×23.321.8÷0.8﹣1.2×5 45÷(5.25÷0.25)16.5×101﹣16.50.96÷0.3×14 1.25×4×2.5×836.45÷(0.82+3.4×0.2)9.07﹣2.64÷0.4 1.5×10112.6×7.5+8.3 13.6×0.85﹣3.6×0.85104×8.586.4÷6.4﹣0.40.25×6.2×0.4 23×6.5+17×6.536÷0.4×0.25(24.6﹣18.1)×3.47.6×9.9+7.6×0.113.6×0.8×12.523.9×8.5﹣3.9×8.5(2.55+9.6÷16)÷0.429.2÷0.25÷48.脱式计算(能简算的要简算)0.75×4×0.25×49.6+9.9×9915.58÷8.2﹣0.724.536÷0.8÷14 2.8×3.6+1.4×2.8 6.3×10.1.9.脱式计算(能简算的要用简算)4.2×7.8+2.2×4.2 9.5×101(8×3.82)×1.25 0.125×720.6×3.9×0.8 42×0.39+4.2×6.110.脱式计算,能简算的要简算0.25×1.25×1618.9﹣18.9÷1.48.37×1.2﹣8.37×0.243×11.8+5.7×118.11.用简便方法计算.6.2+5.18+2.8 15.35﹣(5.35+7.2)3.63﹣1.25+17.37﹣8.75 51.72﹣8.66﹣1.34.12.脱式计算,能简算的要简算.0.7×101﹣0.7 0.125×4.95×8 12.9﹣1.68﹣2.32 567÷20÷5.13.用递等式计算,能简算的要简算.20.16÷7.2+9.8 6.2×2.7+6.5×7.3 32.8+9.6+7.2.14.脱式计算:能简算的要简算15.89﹣(5.89+6.98)0.25×13.7×0.432.7×28+7.3×2815×9.4﹣42 4.9+12.87﹣5.380.05×0.7×20×1.7.15.计算下面各题,能简算的要简算.5.04×28(15.4﹣7.8)×3.5 3.2×4.6+3.2×5.40.25×17.4×4 20﹣6.72﹣3.28 8.33+7.45+1.67+2.55 16.脱式计算.0.2×0.6×0.5×4 (7.5﹣2.3×0.4)÷0.011.2×0.25+2.8×0.25 178.8÷(26.4﹣5.6)17.能简算的要简算3.6﹣1.28+3.09 3.82+2.9+0.18+9.1 9.43﹣(6.28﹣1.57)21.32﹣(6.32+8.3)13.75﹣(3.75+6.48)15﹣7.35﹣2.6518.混合运算,能简便就简便19.81﹣2.68﹣8.32 5.6+6.6﹣5.6+6.60.81×27+0.19×27101×0.19﹣0.19.19.用简便方法计算9.08﹣1.76﹣4.24 18.38﹣(5.38+1.8)﹣8.217.45﹣(8.76﹣6.55)12.87+3.98﹣3.87.20.脱式计算,能简便的用简便方法计算.10.8÷(3.94+6.86)×0.8 0.65×201 12.5×3.9×0.839.8×0.25×4 37.6×8+37.6×2 0.78×99+0.78.21.脱式计算:21.8﹣7.22﹣2.78 9﹣0.24÷1.6×1.19.12+9.12×9﹣6.02 45.2×66.7+66.7×53.8+66.70.25×0.8×0.125×0.4 12.75÷[14.6﹣(1.3+8.2)]0.125×36×(4÷0.5)÷36[(6.1﹣4.6)×0.8﹣1]×0.3615.6﹣(4.1+0.2+6.86÷0.7)[5﹣(1﹣1.2×0.8)]÷41÷0.25+0.4×0.6 13.6×3﹣40.6÷2 25.8+10.5÷(5﹣3.5) 1.42﹣0.36÷6×0.6 49.5×0.2﹣2.07÷23 6.7+3.3÷4.4+5.622.计算下面各题(能简算的要简算)50×(0.8+0.4)7.34×2.1+7.34×6.8+7.34×1.120.5÷1.25÷0.8 9.88×9+9.88.23.计算下列各题(能用简便算法的要用简便算法).12.6÷(1.02+3.18) 5.7×6.9+4.3×6.9(0.81+2.7)÷0.9[(8.4﹣7.9)÷0.25]×1.2.25.能简算的用简便方法计算.(写出主要简便过程,无过程不得分)1.6×3.9×1.25 4.87×2.34+48.7×0.2660.49×9.9 0.05×0.7×20×1.72.5×3.2×12.5 3.95×7.6+3.95×3.4﹣3.95.26.计算下面各题,能简算的要简算7.8×6.9+2.2×6.9 2.36×2.5×4102×0.454.19×99+4.1921.36÷0.8﹣12.9 3.2÷0.8×0.2627.计算(能简算的要简算).6.33×101﹣6.33 1.6×55.4﹣55.4×0.617.68÷5.2+2.7×1.5(1.1﹣0.78)×(2.7﹣1.95)35.6﹣5×1.7315÷0.2÷2.528.脱式计算(能简算的要简算)2.5×1.37×0.4 4.8×0.25×250.89×4.8+0.89×5.2 101×0.78×208.8×1.25×15 4.3×0.8×529.计算下面各题,能简算的要简算.44.28÷0.9÷4.10.25×0.39×47.6+7.6×99 9.07﹣22.78÷3.4 4.8×99+4.8 6.3×10.1 30.下面各题,能简算的就要简算.5.8+3.8×0.25 1.7×(4.65﹣3.87) 1.25×4.3×0.84.5×1020.54×101﹣0.54 3.4×2.5+6.6×2.5.31.计算下列各题.0.45×12×0.2 6.2×2.1﹣2.1 0.9×0.8×1002.8﹣2.8×0.15 2.8×1.43+0.57 72×0.81+10.310﹣6.06+8.5 6×0.25×1.8 7.06×2.4﹣5.832.用简便方法计算.0.25×9.87×4 36.2×1.8+13.8×1.8 0.125×2.3×80.73×102 (6.8+2.6)×5 0.23×98.33.能用简便方法的用简便方法计算12.5×32×2.5 6.8×9.9 7.2÷[1.8×(3.4﹣2.9)].34.用你喜欢的方法计算.3.4×9+3.4 6.4÷0.8﹣1.5×4 3.78÷0.25÷4 17÷[(1.2+0.5)×5].35.用你喜欢的方法计算2.5×1.25×8×0.4 12.8×1.7+87.2×1.7 100﹣4.35﹣5.65.36.用递等式计算(能简算的要简算).4+7.6×15 26.08÷0.25÷419.7+(80.5÷35×0.2)37.计算,能简算的要简算.1.25×2.25×0.8 9.7×99+9.7 4.8×7.8+78×0.523.65×10.1.38.计算下面各题.(能简算的用简便算法)①12.36﹣6.49﹣3.51②8.5×3.8+8.5×6.2③17.3×0.25×8④15.32﹣1.8×5﹣3.46⑤199×2.6⑥3.6÷[(1.3+0.6)×5]39.计算8.5+6.85﹣6.35 3.9+0.1﹣3.9+0.1 12.6﹣(3.75+5.08)40.计算,能简算的要简算6.09﹣9.13÷8.3 3.84×9.6+0.96×61.6 4.86×995.68×4+4.32÷0.256.4×4.5+3.6×4.5.41.脱式计算.10.5+61×18 (3.14+12.6)÷8 4.5÷(15÷3)75+448÷4×19.42.计算:(18.5×3.8+3.8×2.5)÷0.19 [32﹣(7.25+0.75×8)]÷50.43.脱式计算,能简算的就简算:25.32﹣(3.4﹣1.2)12﹣0.62﹣4.38.44.用简便方法计算下面各题.5.12+2.54+4.88 12.5×17.8×0.8 0.24×0.48×49.9×2.5 9.4×5.8+10.6×5.8 0.66×101 4.8×0.25 2.33×0.5×4 1.3×2.5+0.7×2.5 1.26×0.6+1.26×0.4 102×0.55 0.034×0.5×0.245.计算.(怎样简便就怎么计算)13.38+0.98=7.02﹣2.98 6.57﹣(0.68﹣0.39+0.32)13.8÷(1.38×0.2)30.7﹣0.12×2﹣0.76 7.8×1.0118.4﹣6.5+1.6+3.5 7.8÷0.6+7.8÷0.412.13+7.5﹣1.13+2.85 0.125×8.89.4×3.2+6×0.32 9.6×3.6+7.2×0.2.46.计算下面各题,能简算得要简算.96÷(100×0.48) 3.6÷(1.2+0.5)×6(967﹣31)÷(17+48)72×10.1+27×10.1.47.用自己喜欢的方法计算.3.4×7.8÷3.9 54÷(6.86+3.94)48.用简便方法计算0.486+0.01+3.99 17.5×2.3﹣7.5×2.3 1.25×11×4×0.84.8×39+61×4.8 45.55﹣(6.82+15.55) 3.2×99+3.22.5×56+4.5×56 (31.6﹣11.7)÷2.5÷43.6×0.9+3.6×0.149.计算下列各题.(能简算的要简算)7.5﹣2.4÷0.8×2.5 12.5×17+83×12.5399×2.5 25÷(2.5÷0.4)3.25×67+5.75×67+67 230÷2.5×7.5 6.3+0.84+3.7+8.16 100﹣(2.72+10.8)÷0.250.脱式计算0.25×3.25×4 6.72+3.2÷2.521.36÷0.4﹣23.40.8×4.5+1.2×4.5.小数除法脱式运算+简算260道参考答案与试题解析 一.计算题(共50小题)1.【解答】解:(1)32×12.5×0.25=4×8×12.5×0.25=(4×0.25)×(8×12.5)=1×100=100(2)6.1×4.2+5.8×6.1=6.1×(4.2+5.8)=6.1×10=61(3)1.7÷2.5÷0.4=1.7÷(2.5×0.4)=1.7÷1=1.7(4)16.1﹣4.2﹣5.8=16.1﹣(4.2+5.8)=16.1﹣10=6.1 2.【解答】解:(1)(0.6×0.8+0.12)÷1.2=0.6÷1.2=0.5答:商是0.5.(2)(14.81+5.19)×(14.81﹣5.19)=20×9.62=192.4答:积是192.4.(3)[(2.7+4.5)÷12]×0.3=[7.2÷12]×0.3=0.6×0.3=0.18答:积是0.18. 3.【解答】解:①4.8÷(1.2÷0.5)=4.8÷2.4=2②12.8﹣12.8÷5=12.8﹣2.56=10.24③71.4÷(7×6)=71.4÷7÷6=10.2÷6=1.7 4.【解答】解:①0.65×101﹣0.65=0.65×(101﹣1)=0.65×100=65②12.6﹣3.25+6.75=12.6+(6.75﹣3.25)=12.6+3.5=16.1③6.35÷0.2÷0.5=6.35÷(0.2×0.5)=6.35÷0.1=63.5④5.7×1.2÷19=5.7÷19×1.2=0.3×1.2=0.36⑤1.25×3.63×0.8=(1.25×0.8)×3.63=1×3.63=3.63 5.【解答】解:①0.11×1.8+8.2×0.11=0.11×(1.8+8.2)=0.11×10=1.1②3.5﹣3.5×0.98=3.5×(1﹣0.98)=3.5×0.02=0.07③0.75×18÷0.15=0.75÷0.15×18=5×18=90④0.25×4.78×8=0. 25×8×4.78=2×4.78=9.56 6.【解答】解:①17.3÷0.125÷8=17.3÷(0.125×8)=17.3÷1=17.3②14.72×0.7+5.28×0.7=(14.72+5.28)×0.7=20×0.7=14③3.5÷0.56=(3.5÷0.7)÷(0.56÷0.7)=5÷8=0.625④8.5×9.9+0.82=8.5×(10﹣0.1)+0.82=8.5×10﹣8.5×0.1+0.82=85﹣0.85+0.82=85﹣(0.85﹣0.82)=85﹣0.03=84.97 7.【解答】解:(1)38.75﹣(24.5+8.75)=38.75﹣24.5﹣8.75=38.75﹣8.75﹣24.5=30﹣24.5=5.5;(2)0.4×2.32×0.25=0.4×0.25×2.32=0.1×2.32=0.232;(3)0.75×101=0.75×(100+1)=0.75×100+0.75×1=75+0.75=75.75;(4)4.2﹣3.2×0.9=4.2﹣2.88=1.32;(5)7.56×99+7.56=7.56×(99+1)=7.56×100=756;(6)70.3﹣17.48÷7.6=70.3﹣2.3=68;(7)3.64÷5.2×23.3=0.7×23.3=16.31;(8)21.8÷0.8﹣1.2×5=27.25﹣6=21.25;(9)45÷(5.25÷0.25)=45÷21=;(10)16.5×101﹣16.5=16.5×(101﹣1)=16.5×100=1650;(11)0.96÷0.3×14=3.2×14=44.8;(12)1.25×4×2.5×8=(1.25×8)×(4×2.5)=10×10=100;(13)36.45÷(0.82+3.4×0.2)=36.45÷(0.82+0.68)=36.45÷1.5=24.3;(14)9.07﹣2.64÷0.4=9.07﹣6.6=2.47;(15)1.5×101=1.5×(100+1)=1.5×100+1.5×1=150+1.5=151.5;(16)12.6×7.5+8.3=94.5+8.3=102.8;(17)13.6×0.85﹣3.6×0.85=(13.6﹣3.6)×0.85=10×0.85=8.5;(18)104×8.5=(100+4)×8.5=100×8.5+4×8.5=850+34=884;(19)86.4÷6.4﹣0.4=13.5﹣0.4=13.1;(20)0.25×6.2×0.4=0.25×0.4×6.2=0.1×6.2=0.62;(21)23×6.5+17×6.5=(23+17)×6.5=40×6.5=260;(22)36÷0.4×0.25=90×0.25=22.5;(23)(24.6﹣18.1)×3.4=6.5×3.4=22.1;(24)7.6×9.9+7.6×0.1=7.6×(9.9+0.1)=7.6×10=76;(25)13.6×0.8×12.5=13.6×(0.8×12.5)=13.6×10=136;(26)23.9×8.5﹣3.9×8.5=(23.9﹣3.9)×8.5=20×8.5=170;(27)(2.55+9.6÷16)÷0.42=(2.55+0.6)÷0.42=3.15÷0.42=7.5;(28)9.2÷0.25÷4=9.2÷(0.25×4)=9.2÷1=9.2. 8.【解答】解:(1)0.75×4×0.25×4=(0.75×4)×(0.25×4)=3×1=3(2)9.6+9.9×99=9.6+9.9×(100﹣1)=9.6+9.9×100﹣9.9=9.6+990﹣9.9=989.7(3)15.58÷8.2﹣0.72=1.9﹣0.72=1.18(4)4.536÷0.8÷14=5.67÷14=0.405(5)2.8×3.6+1.4×2.8=2.8×(3.6+1.4)=2.8×5=14(6)6.3×10.1=6.3×(10+0.1)=6.3×10+6.3×0.1=63+0.63=63.63 9.【解答】解:(1)4.2×7.8+2.2×4.2=4.2×(7.8+2.2 )=4.2×10=42(2)9.5×101=9.5×(100+1)=9.5×100+9.5=950+9.5=959.5(3)(8×3.82)×1.25 =(8×1.25)×3.82=10×3.82=38.2(4)0.125×72=0.125×8×9=1×9=9(5)0.6×3.9×0.8 =2.34×0.8=1.872(6)42×0.39+4.2×6.1=42×0.39+42×0.61=42×(0.39+0.61)=42×1=42 10.【解答】解:(1)0.25×1.25×16=0.25×1.25×(2×8)=(0.25×2)×(1.25×8)=0.5×10=5(2)18.9﹣18.9÷1.4=18.9﹣13.5=5.4(3)8.37×1.2﹣8.37×0.2=8.37×(1.2﹣0.2)=8.37×1=8.37(4)43×11.8+5.7×118=43×11.8+57×11.8=(43+57)×11.8=100×11.8=1180 11.【解答】解:(1)6.2+5.18+2.8 =6.2+2.8+5.18 =9+5.18=14.18 (2)15.35﹣(5.35+7.2)=15.35﹣5.35﹣7.2=10﹣7.2=2.8(3)3.63﹣1.25+17.37﹣8.75=(3.63+17.37)﹣(1.25+8.75)=21﹣10=11(4)51.72﹣8.66﹣1.34=51.72﹣(8.66+1.34)=51.72﹣10=41.72 12.【解答】解:(1)0.7×101﹣0.7 =0.7×(101﹣1)=0.7×100=70(2)0.125×4.7×8=0.125×8×4.7=1×4.7=4.7(3)12.9﹣1.68﹣2.32=12.9﹣(1.68+2.32)=12.9﹣4=8.9(4)567÷20÷5=567÷(20×5)=567÷100=5.67 13.【解答】解:①20.16÷7.2+9.8 =2.8+9.8=12.6;②6.2×2.7+6.5×7.3 =16.74+47.45=64.19;③32.8+9.6+7.2=9.6+(32.8+7.2)=9.6+40=49.6. 14.【解答】解:(1)15.89﹣(5.89+6.98)=15.89﹣5.89﹣6.98=10﹣6.98=3.02;(2)0.25×13.7×0.4=0.25×0.4×13.7=0.1×13.7=1.37;(3)32.7×28+7.3×28=(32.7+7.3)×28=40×28=1120;(4)15×9.4﹣42=141﹣42=99;(5)4.9+12.87﹣5.38=17.77﹣5.38=12.39;(6)0.05×0.7×20×1.7=0.05×20×0.7×1.7=1×0.7×1.7=0.7×1.7=1.19. 15.【解答】解:(1)5.04×28=(5+0.04)×28=5×28+0.04×28=140+1.12=141.12;(2)(15.4﹣7.8)×3.5 =7.6×3.5 =26.6;(3)3.2×4.6+3.2×5.4=3.2×(4.6+5.4)=3.2×10=32;(4)0.25×17.4×4=0.25×4×17.4=1×17.4=17.4;(5)20﹣6.72﹣3.28=20﹣(6.72+3.28)=20﹣10=10;(6)8.33+7.45+1.67+2.55=8.33+1.67+7.45+2.55=(8.33+1.67)+(7.45+2.55)=10+10=20. 16.【解答】解:(1)0.2×0.6×0.5×4 =(0.2×0.5)×(0.6×4)=0.1×2.4=0.24;(2)(7.5﹣2.3×0.4)÷0.01=(7.5﹣0.92)÷0.01=6.58÷0.01=658;(3)1.2×0.25+2.8×0.25=(1.2+2.8)×0.25=4×0.25=1;(4)178.8÷(26.4﹣5.6)=178.8÷20.8=. 17.【解答】解:(1)3.6﹣1.28+3.09=2.32+3.09=5.41(2)3.82+2.9+0.18+9.1 =(3.82+0.18)+(9.1+2.9)=4+12=16(3)9.43﹣(6.28﹣1.57)=9.43+1.57﹣6.28=11﹣6.28=4.72(4)21.32﹣(6.32+8.3)=21.32﹣6.32﹣8.3=15﹣8.3=6.7(5)13.75﹣(3.75+6.48)=13.75﹣3.75﹣6.48=10﹣6.48=3.52(6)15﹣7.35﹣2.65=15﹣(7.35+2.65)=15﹣10=5 18.【解答】解:①19.81﹣2.68﹣8.32=19.81﹣(2.68+8.32)=19.81﹣11=8.81②5.6+6.6﹣5.6+6.6=(5.6﹣5.6)+(6.6+6.6)=0+13.2=13.2③0.81×27+0.19×27=27×(0.81+0.19)=27×1=27④101×0.19﹣0.19=(101﹣1)×0.19=100×0.19=19 19.【解答】解:(1)9.08﹣1.76﹣4.24 =9.08﹣(1.76+4.24)=9.08﹣6=3.08;(2)18.38﹣(5.38+1.8)﹣8.2=18.38﹣7.18﹣8.2=11.2﹣8.2=3;(3)17.45﹣(8.76﹣6.55)=17.45﹣8.76+6.55=17.45+6.55﹣8.76=24﹣8.76=15.24;(4)12.87+3.98﹣3.87=12.87﹣3.87+3.98=9+3.98=12.98. 20.【解答】解:①10.8÷(3.94+6.86)×0.8 =10.8÷10.8×0.8=1×0.8=0.8②0.65×201 =0.65×(200+1)=0.65×200+0.65×1=130+0.65=130.65③12.5×3.9×0.8=12.5×0.8×3.9=10×3.9=39④39.8×0.25×4 =39.8×(0.25×4)=39.8×1=39.8⑤37.6×8+37.6×2 =37.6×(8+2)=37.6×10=376 ⑥0.78×99+0.78=0.78×(99+1)=0.78×100=78 21.【解答】解:(1)21.8﹣7.22﹣2.78=21.8﹣(7.22+2.78)=21.8﹣10=11.8(2)9﹣0.24÷1.6×1.1=9﹣0.15×1.1=9﹣0.165=8.835(3)9.12+9.12×9﹣6.02=9.12×(1+9)﹣6.02=9.12×10﹣6.02=91.2﹣6.02=85.18(4)45.2×66.7+66.7×53.8+66.7=(45.2+53.8+1)×66.7=100×66.7=6670(5)0.25×0.8×0.125×0.4=(0.25×0.4)×(0.125×0.8)=0.1×0.1=0.01(6)12.75÷[14.6﹣(1.3+8.2)]=12.75÷[14.6﹣9.5]=12.75÷5.1=2.5(7)0.125×36×(4÷0.5)÷36=0.125×(4÷0.5)×(36÷36)=0.125×8×1=1(8)[(6.1﹣4.6)×0.8﹣1]×0.36=[1.5×0.8﹣1]×0.36=[1.2﹣1]×0.36=0.2×0.36=0.072(9)15.6﹣(4.1+0.2+6.86÷0.7)=15.6﹣(4.1+0.2+9.8)=15.5﹣(4.1+10)=15.5﹣14.1=1.4(10)[5﹣(1﹣1.2×0.8)]÷4=[5﹣(1﹣0.96)]÷4=[5﹣0.04]÷4=4.96÷4=1.24(11)1÷0.25+0.4×0.6=4+0.24=4.24(12)13.6×3﹣40.6÷2=40.8﹣20.3=20.5(13)25.8+10.5÷(5﹣3.5)=25.8+10.5÷1.5=25.8+7=32.8(14)1.42﹣0.36÷6×0.6=1.42﹣0.36=1.07(15)49.5×0.2﹣2.07÷23=9.9﹣0.09=9.81(16)6.7+3.3÷4.4+5.6=6.7+0.75+5.6=7.45+5.6=13.05 22.【解答】解:①50×(0.8+0.4)=50×0.8+50×0.4=40+20=60②7.34×2.1+7.34×6.8+7.34×1.1=7.34×(2.1+6.8+1.1)=7.34×10=73.4③20.5÷1.25÷0.8=20.5÷(1.25×0.8)=20.5÷1=20.5④9.88×9+9.88=9.88×(9+1)=9.88×10=98.8 23.【解答】解:(1)12.6÷(1.02+3.18)=12.6÷4.2=3;(2)5.7×6.9+4.3×6.9=(5.7+4.3)×6.9=10×6.9=69;(3)(0.81+2.7)÷0.9=3.51÷0.9=3.9;(4)[(8.4﹣7.9)÷0.25]×1.2=[0.5÷0.25]×1.2=2×1.2=2.4. 24.【解答】解:(1)25×1.25×32 =25×1.25×8×4=(25×4)×(1.25×8)=100×10=1000(2)(+)×35=×35+×35=10+7=17(3)78×=(79﹣1)×=79×﹣=3﹣=2(4)÷+=÷= 25.【解答】解:(1)1.6×3.9×1.25=0.8×2×3.9×1.25=(0.8×1.25)×(2×3.9)=1×7.8=7.8(2)4.87×2.34+48.7×0.266=4.87×2.34+4.87×2.66=4.87×(2.34+2.66)=4.87×5=24.35(3)0.49×9.9 =0.49×(10﹣0.1)=0.49×10﹣0.49×0.1=4.9﹣0.049=4.851(4)0.05×0.7×20×1.7=(0.05×20)×(0.7×1.7)=1×1.19=1.19(5)2.5×3.2×12.5 =2.5×0.4×8×12.5 =(2.5×0.4)×(8×12.5)=1×100=100(6)3.95×7.6+3.95×3.4﹣3.95=3.95×(7.6+3.4﹣1)=3.95×10=39.5 26.【解答】解:(1)7.8×6.9+2.2×6.9=(7.8+2.2)×6.9=10×6.9=69(2)2.36×2.5×4=2.36×(2.5×4)=2.36×10=23.6(3)102×0.45=(100+2)×0.45=100×0.45+2×0.45=45+0.9=45.9(4)4.19×99+4.19=4.19×(99+1)=4.19×100=419(5)21.36÷0.8﹣12.9=26.7﹣12.9=13.8(6)3.2÷0.8×0.26=4×0.26=1.04 27.【解答】解:(1)6.33×101﹣6.33=6.33×(101﹣1)=6.33×100=633;(2)1.6×55.4﹣55.4×0.6=(1.6﹣0.6)×55.4=1×55.4=55.4;(3)17.68÷5.2+2.7×1.5=3.4+4.05=7.45;(4)(1.1﹣0.78)×(2.7﹣1.95)=0.32×0.75=0.24;(5)35.6﹣5×1.73=35.6﹣8.65=26.95;(6)15÷0.2÷2.5=15÷(0.2×2.5)=15÷0.5=30. 28.【解答】解:(1)2.5×1.37×0.4=2.5×0.4×1.37=1×1.37=1.37;(2)4.8×0.25×25=(4×4×0.3)×0.25×25=(4×0.25)×(4×25)×0.3=1×100×0.3=30;(3)0.89×4.8+0.89×5.2=0.89×(4.8+5.2)=0.89×10=8.9;(4)101×0.78×20=101×(0.78×20)=101×15.6=(100+1)×15.6=100×15.6+1×15.6=1560+15.6=1575.6;(5)8.8×1.25×15=(8×1.1)×1.25×15=(8×1.25)×(1.1×15)=10×16.5=165;(6)4.3×0.8×5=4.3×(0.8×5)=4.3×4=17.2. 29.【解答】解:(1)44.28÷0.9÷4.1=49.2÷4.1=12;(2)0.25×0.39×4=(0.25×4)×0.39=1×0.39=0.39;(3)7.6+7.6×99=7.6×(1+99)=7.6×100=760;(4)9.07﹣22.78÷3.4=9.07﹣6.7=2.37;(5)4.8×99+4.8=4.8×(99+1)=4.8×100=480;(6)6.3×10.1=6.3×(10+0.1)=6.3×10+6.3×0.1=63+0.63=63.63. 30.【解答】解:(1)5.8+3.8×0.25=5.8+0.95=6.75(2)1.7×(4.65﹣3.87)=1.7×0.78=1.326(3)1.25×4.3×0.8=1.25×0.8×4.3=1×4.3=4.3(4)4.5×102=4.5×(100+2)=4.5×100+4.5×2=450+9=459(5)0.54×101﹣0.54=0.54×(101﹣1)=0.54×100=54(6)3.4×2.5+6.6×2.5=(3.4+6.6)×2.5=10×2.5=25 31.【解答】解:①0.45×12×0.2=0.45×0.2×12=0.09×12=1.08 ②6.2×2.1﹣2.1=2.1×(6.2﹣1)=2.1×5.2=10.92③0.9×0.8×100=0.72×100=72④2.8﹣2.8×0.15 =2.8×(1﹣0.15)=2.8×0.85=2.38 ⑤2.8×1.43+0.57 =4.004+0.57=4.574⑥72×0.81+10.3=58.32+10.3=68.62⑦10﹣6.06+8.5=3.94+8.5=12. 44 ⑧6×0.25×1.8 =1.5×1.8=2.7⑨7.06×2.4﹣5.8 =16.944﹣5.8=11.144 32.【解答】解:(1)0.25×9.87×4 =0.25×4×9.87=1×9.87=9.87;(2)36.2×1.8+13.8×1.8 =(36.2+13.8)×1.8=50×1.8=90;(3)0.125×2.3×8=0.125×8×2.3=1×2.3=2.3;(4)0.73×102 =0.73×(100+2)=0.73×100+0.73×2=73+1.46=74.46;(5)(6.8+2.6)×5 =6.8×5+2.6×5=34+13=47;(6)0.23×98=0.23×(100﹣2)=0.23×100﹣0.23×2=23﹣0.46=22.54. 33.【解答】解:(1)12.5×32×2.5=12.5×4×8×2.5=(12.5×8)×(2.5×4)=100×10=1000;(2)6.8×9.9 =6.8×(10﹣0.1)=6.8×10﹣6.8×0.1=68﹣0.68=67.32;(3)7.2÷[1.8×(3.4﹣2.9)]=7.2÷[1.8×0.5]=7.2÷0.9=8. 34.【解答】解:(1)3.4×9+3.4=30.6+3.4=34;(2)6.4÷0.8﹣1.5×4=8﹣6=2;(3)3.78÷0.25÷4=3.78÷(0.25×4)=3.78÷1=3.78;(4)17÷[(1.2+0.5)×5]=17÷[1.7×5]=17÷8.5=2. 35.【解答】解:(1)2.5×1.25×8×0.4=(2.5×0.4)×(1.25×8)=1×10=10;(2)12.8×1.7+87.2×1.7=(12.8+87.2)×1.7=100×1.7=170;(3)100﹣4.35﹣5.65=100﹣(4.35+5.65)=100﹣10=90. 36.【解答】解:(1)4+7.6×15 =4+114=118;(2)26.08÷0.25÷4=26.08÷(0.25×4)=26.08÷1=26.08;(3)19.7+(80.5÷35×0.2)=19.7+(2.3×0.2)=19.7+0.46=20.16. 37.【解答】解:(1)1.25×2.25×0.8=1.25×0.8×2.25=1×2.25=2.25;(2)9.7×99+9.7=9.7×(99+1)=9.7×100=970;(3)4.8×7.8+78×0.52=4.8×7.8+7.8×5.2=(4.8+5.2)×7.8=10×7.8=78;(4)3.65×10.1=3.65×(10+0.1)=3.65×10+3.65×0.1=36.5+0.365=36.865. 38.【解答】解:①12.36﹣6.49﹣3.51=12.36﹣(6.49+3.51)=12.36﹣10=2.36;②8.5×3.8+8.5×6.2=8.5×(3.8+6.2)=8.5×10=85;③17.3×0.25×8=17.3×(0.25×8)=17.3×2=34.6;④15.32﹣1.8×5﹣3.46=15.32﹣9﹣3.46=6.32﹣3.46=2.86;⑤199×2.6=(200﹣1)×2.6=200×2.6﹣1×2.6=520﹣2.6=517.4;⑥3.6÷[(1.3+0.6)×5]=3.6÷[1.9×5]=3.6÷9.5=. 39.【解答】解:(1)8.5+6.85﹣6.35=8.5+(6.85﹣6.35)=8.5+0.5=9;(2)3.9+0.1﹣3.9+0.1 =(3.9﹣3.9)+(0.1+0.1)=0+0.2=0.2;(3)12.6﹣(3.75+5.08)=12.6﹣8.83=3.77. 40.【解答】解:(1)6.09﹣9.13÷8.3=6.09﹣1.1=4.99(2)3.84×9.6+0.96×61.6 =(3.84+6.16)×9.6=10×9.6=96(3)4.86×99=4.86×(100﹣1)=4.86×100﹣4.86=486﹣4.86=481.14(4)5.68×4+4.32÷0.25=5.68×4+4.32×4=(5.68+4.32)×4=10×4=40(5)6.4×4.5+3.6×4.5=(6.4+3.6)×4.5=10×4.5=45 41.【解答】解:①10.5+61×18=10.5+1098=1108.5 ②(3.14+12.6)÷8=15.74÷8=1.9675③4.5÷(15÷3)=4.5÷5=0.9④75+448÷4×19=75+112×19=75+2128=2203 42.【解答】解:(1)(18.5×3.8+3.8×2.5)÷0.19 =3.8×(18.5+2.5)÷0.19 =3.8×21÷0.19=3.8÷0.19×21=200×21=4200(2)[32﹣(7.25+0.75×8)]÷50=[32﹣(7.25+6)]÷50=[32﹣13.25]÷50=18.75÷50=0.375 43.【解答】解:①25.32﹣(3.4﹣1.2)=25.32﹣2.2=23.12②12﹣0.62﹣4.38=12﹣(0.62+4.38)=12﹣5=7 44.【解答】解:(1)5.12+2.54+4.88=5.12+4.88+2.54=10+2.54=12.54;(2)12.5×17.8×0.8=12.5×0.8×17.8=10×17.8=178;(3)0.24×0.48×4=0.1152×4=0.4608;(4)9.9×2.5=(10﹣0.1)×2.5=10×2.5﹣0.1×2.5=25﹣0.25=24.75;(5)9.4×5.8+10.6×5.8=(9.4+10.6)×5.8=20×5.8=116;(6)0.66×101=0.66×(100+1)=0.66×100+0.66×1=66+0.66=66.66;(7)4.8×0.25=(1.2×4)×0.25=1.2×(4×0.25)=1.2×1=1.2;(8)2.33×0.5×4 =2.33×(0.5×4)=2.33×2=4.66;(9)1.3×2.5+0.7×2.5=(1.3+0.7)×2.5=2×2.5=5;(10)1.26×0.6+1.26×0.4=1.26×(0.6+0.4)=1.26×1=1.26;(11)102×0.55=(100+2)×0.55=100×0.55+2×0.55=55+1.1=56.1;(12)0.034×0.5×0.2=0.034×(0.5×0.2)=0.034×0.1=0.0034. 45.【解答】解:(1)13.38+0.98=13.38+(1﹣0.02)=13.38+1﹣0.02=14.38﹣0.02=14.36;(2)7.02﹣2.98 =7.02﹣(3﹣0.02)=7.02﹣3+0.02 =4.02+0.02=4.04;(3)6.57﹣(0.68﹣0.39+0.32)=6.57﹣(0.68+0.32﹣0.39)=6.57﹣(1﹣0.39)=6.57﹣0.61=5.96;(4)13.8÷(1.38×0.2)=13.8÷1.38÷0.2=10÷0.2=50;(5)30.7﹣0.12×2﹣0.76=30.7﹣0.24﹣0.76=30.7﹣(0.24+0.76)=30.7﹣1=29.7;(6)7.8×1.01=7.8×(1+0.01)=7.8×1+7.8×0.01=7.8+0.078=7.878;(7)18.4﹣6.5+1.6+3.5 =(18.4+1.6)﹣(6.5﹣3.5)=20﹣3=17;(8)7.8÷0.6+7.8÷0.4=13+19.5=32.5;(9)12.13+7.5﹣1.13+2.85=(12.13﹣1.13)+(7.5+2.85)=11﹣10.35=0.65;(10)0.125×8.8=0.125×(8+0.8)=0.125×8+0.125×0.8=1+0.1=1.1;(11)9.4×3.2+6×0.32=9.4×3.2+0.6×3.2=(9.4+0.6)×3.2=10×3.2=32;(12)9.6×3.6+7.2×0.2=9.6×3.6+3.6×2×0.2=9.6×3.6+3.6×0.4=(9.6+0.4)×3.6=10×3.6=36. 46.【解答】解:(1)96÷(100×0.48)=96÷48=2;(2)3.6÷(1.2+0.5)×6=3.6÷1.7×6=×6=;(3)(967﹣31)÷(17+48)=936÷65=14.4;(4)72×10.1+27×10.1=(72+27)×10.1=99×10.1=99×(10+0.1)=99×10+99×0.1=990+9.9=999.9. 47.【解答】解:(1)3.4×7.8÷3.9=26.52÷3.9=6.8;(2)54÷(3.94+6.86)=54÷10.8=5. 48.【解答】解:①0.486+0.01+3.99 =0.486+(0.01+3.99)=0.486+4=4.486 ②17.5×2.3﹣7.5×2.3 =2.3×(17.5﹣7.5)=2.3×10=23 ③1.25×11×4×0.8=(1.25×0.8)×(11×4)=1×44=44④4.8×39+61×4.8=4.8×(39+61)=4.8×100=480⑤45.55﹣(6.82+15.55)=45.55﹣6.82﹣15.55=45.55﹣15.55﹣6.82=30﹣6.82=23.18⑥3.2×99+3.2=3.2×(99+1)=3.2×100=320⑦2.5×56+4.5×56 =56×(2.5+4.5)=56×7=392⑧(31.6﹣11.7)÷2.5÷4 =19.9÷(2.5×4)=19.9÷10=1.99⑨3.6×0.9+3.6×0.1=3.6×(0.9+0.1)=3.6×1=3.6 49.【解答】解:(1)7.5﹣2.4÷0.8×2.5 =7.5﹣3×2.5=7.5﹣7.5=0;(2)12.5×17+83×12.5=12.5×(17+83)=12.5×100=1250;(3)399×2.5=(400﹣1)×2.5=400×2.5﹣2.5=1000﹣2.5=997.25;(4)25÷(2.5÷0.4)=25÷2.5×0.4=10×0.4=4;(5)3.25×67+5.75×67+67 =(3.25+5.75+1)×67=10×67=670;(6)230÷2.5×7.5=92×7.5=690;(7)6.3+0.84+3.7+8.16=(6.3+3.7)+(0.84+8.16)=10+9=19;(8)100﹣(2.72+10.8)÷0.2=100﹣13.52÷0.2=100﹣67.6=32.4. 50.【解答】解:(1)0.25×3.25×4=0.25×4×3.25=1×3.25=3.25(2)6.72+3.2÷2.5=6.72+1.28=8(3)21.36÷0.4﹣23.4=53.4﹣23.4=30(4)0.8×4.5+1.2×4.5=(0.8+1.2)×4.5=2×4.5=9 。

小数除法脱式运算+简算260道 含问题详解

小数除法脱式运算+简算260道  含问题详解

小数除法脱式运算+简算260道一.计算题(共50小题)1.用你喜欢的方法计算.32×12.5×0.25 6.1×4.2+5.8×6.1 1.7÷2.5÷0.416.1﹣4.2﹣5.8.3.脱式计算4.8÷(1.2÷0.5)12.8﹣12.8÷571.4÷(7×6)4.用你喜欢的方法计算0.65×101﹣0.65 12.6﹣3.25+6.756.35÷0.2÷0.5 5.7×1.2÷19 1.25×3.63×0.8.5.我能用喜欢的方法计算下面各题.0.11×1.8+8.2×0.11 3.5﹣3.5×0.980.75×18÷0.150.25×4.78×8.6.能简算的要简算.17.3÷0.125÷8 14.72×0.7+5.28×0.73.5÷0.56 8.5×9.9+0.82.7.递等式计算,有简便运算的用简便方法38.75﹣(24.5+8.75)0.4×2.32×0.250.75×101 4.2﹣3.2×0.97.56×99+7.5670.3﹣17.48÷7.6 3.64÷5.2×23.321.8÷0.8﹣1.2×545÷(5.25÷0.25)16.5×101﹣16.50.96÷0.3×14 1.25×4×2.5×836.45÷(0.82+3.4×0.2)9.07﹣2.64÷0.4 1.5×10112.6×7.5+8.3 13.6×0.85﹣3.6×0.85104×8.586.4÷6.4﹣0.40.25×6.2×0.423×6.5+17×6.536÷0.4×0.25(24.6﹣18.1)×3.47.6×9.9+7.6×0.113.6×0.8×12.523.9×8.5﹣3.9×(2.55+9.6÷16)÷0.429.2÷0.25÷48.58.脱式计算(能简算的要简算)0.75×4×0.25×49.6+9.9×9915.58÷8.2﹣0.724.536÷0.8÷14 2.8×3.6+1.4×2.8 6.3×10.1.9.脱式计算(能简算的要用简算)9.5×101(8×3.82)×1.25 4.2×7.8+2.2×4.20.125×720.6×3.9×0.8 42×0.39+4.2×6.110.脱式计算,能简算的要简算0.25×1.25×1618.9﹣18.9÷1.48.37×1.2﹣8.37×0.243×11.8+5.7×118.11.用简便方法计算.6.2+5.18+2.8 15.35﹣(5.35+7.2)3.63﹣1.25+17.37﹣8.75 51.72﹣8.66﹣1.34.12.脱式计算,能简算的要简算.0.7×101﹣0.7 0.125×4.95×8 12.9﹣1.68﹣2.32 567÷20÷5.13.用递等式计算,能简算的要简算.20.16÷7.2+9.8 6.2×2.7+6.5×7.3 32.8+9.6+7.2.14.脱式计算:能简算的要简算15.89﹣(5.89+6.98)0.25×13.7×0.432.7×28+7.3×2815×9.4﹣42 4.9+12.87﹣5.380.05×0.7×20×1.7.15.计算下面各题,能简算的要简算.3.2×4.6+3.2×5.45.04×28(15.4﹣7.8)×3.520﹣6.72﹣3.28 8.33+7.45+1.67+2.550.25×17.4×416.脱式计算.0.2×0.6×0.5×4 (7.5﹣2.3×0.4)÷0.011.2×0.25+2.8×0.25 178.8÷(26.4﹣5.6)17.能简算的要简算3.6﹣1.28+3.09 3.82+2.9+0.18+9.1 9.43﹣(6.28﹣1.57)21.32﹣(6.32+8.3)13.75﹣(3.75+6.48)15﹣7.35﹣2.6518.混合运算,能简便就简便19.81﹣2.68﹣8.32 5.6+6.6﹣5.6+6.60.81×27+0.19×27101×0.19﹣0.19.19.用简便方法计算9.08﹣1.76﹣4.24 18.38﹣(5.38+1.8)﹣8.2 17.45﹣(8.76﹣6.55)12.87+3.98﹣3.87.20.脱式计算,能简便的用简便方法计算.10.8÷(3.94+6.86)×0.8 0.65×201 12.5×3.9×0.839.8×0.25×4 37.6×8+37.6×2 0.78×99+0.78.21.脱式计算:21.8﹣7.22﹣2.78 9﹣0.24÷1.6×1.19.12+9.12×9﹣6.020.25×0.8×0.125×0.4 12.75÷[14.6﹣(1.3+8.2)] 45.2×66.7+66.7×53.8+66.70.125×36×(4÷0.5)÷36[(6.1﹣4.6)×0.8﹣1]×0.3615.6﹣(4.1+0.2+6.86÷0.7)[5﹣(1﹣1.2×0.8)]÷41÷0.25+0.4×0.6 13.6×3﹣40.6÷225.8+10.5÷(5﹣3.5) 1.42﹣0.36÷6×0.6 49.5×0.2﹣2.07÷236.7+3.3÷4.4+5.622.计算下面各题(能简算的要简算)50×(0.8+0.4)7.34×2.1+7.34×6.8+7.34×1.120.5÷1.25÷0.8 9.88×9+9.88.23.计算下列各题(能用简便算法的要用简便算法).12.6÷(1.02+3.18) 5.7×6.9+4.3×6.9(0.81+2.7)÷0.9[(8.4﹣7.9)÷0.25]×1.2.25.能简算的用简便方法计算.(写出主要简便过程,无过程不得分)1.6×3.9×1.25 4.87×2.34+48.7×0.2660.49×9.90.05×0.7×20×1.72.5×3.2×12.53.95×7.6+3.95×3.4﹣3.95.26.计算下面各题,能简算的要简算7.8×6.9+2.2×6.9 2.36×2.5×4102×0.454.19×99+4.1921.36÷0.8﹣12.9 3.2÷0.8×0.26 27.计算(能简算的要简算).6.33×101﹣6.33 1.6×55.4﹣55.4×0.617.68÷5.2+2.7×1.5(1.1﹣0.78)×(2.7﹣1.95)35.6﹣5×1.7315÷0.2÷2.5 28.脱式计算(能简算的要简算)2.5×1.37×0.4 4.8×0.25×250.89×4.8+0.89×5.2101×0.78×208.8×1.25×15 4.3×0.8×529.计算下面各题,能简算的要简算.44.28÷0.9÷4.10.25×0.39×47.6+7.6×999.07﹣22.78÷3.4 4.8×99+4.8 6.3×10.1 30.下面各题,能简算的就要简算.5.8+3.8×0.25 1.7×(4.65﹣3.87) 1.25×4.3×0.84.5×1020.54×101﹣0.54 3.4×2.5+6.6×2.5.31.计算下列各题.0.45×12×0.2 6.2×2.1﹣2.1 0.9×0.8×1002.8﹣2.8×0.15 2.8×1.43+0.57 72×0.81+10.310﹣6.06+8.5 6×0.25×1.8 7.06×2.4﹣5.832.用简便方法计算.0.25×9.87×4 36.2×1.8+13.8×1.8 0.125×2.3×80.73×102 (6.8+2.6)×5 0.23×98.33.能用简便方法的用简便方法计算12.5×32×2.5 6.8×9.9 7.2÷[1.8×(3.4﹣2.9)].34.用你喜欢的方法计算.3.4×9+3.4 6.4÷0.8﹣1.5×4 3.78÷0.25÷4 17÷[(1.2+0.5)×5].35.用你喜欢的方法计算2.5×1.25×8×0.4 12.8×1.7+87.2×1.7 100﹣4.35﹣5.65.36.用递等式计算(能简算的要简算).4+7.6×15 26.08÷0.25÷419.7+(80.5÷35×0.2)37.计算,能简算的要简算.1.25×2.25×0.8 9.7×99+9.7 4.8×7.8+78×0.523.65×10.1.38.计算下面各题.(能简算的用简便算法)①12.36﹣6.49﹣3.51②8.5×3.8+8.5×6.2③17.3×0.25×8④15.32﹣1.8×5﹣3.46⑤199×2.6⑥3.6÷[(1.3+0.6)×5]39.计算8.5+6.85﹣6.35 3.9+0.1﹣3.9+0.1 12.6﹣(3.75+5.08)40.计算,能简算的要简算6.09﹣9.13÷8.3 3.84×9.6+0.96×61.6 4.86×995.68×4+4.32÷0.256.4×4.5+3.6×4.5.41.脱式计算.10.5+61×18 (3.14+12.6)÷8 4.5÷(15÷3)75+448÷4×19.42.计算:(18.5×3.8+3.8×2.5)÷0.19 [32﹣(7.25+0.75×8)]÷50.43.脱式计算,能简算的就简算:25.32﹣(3.4﹣1.2)12﹣0.62﹣4.38.44.用简便方法计算下面各题.5.12+2.54+4.88 12.5×17.8×0.8 0.24×0.48×49.9×2.52.33×0.5×49.4×5.8+10.6×5.8 0.66×101 4.8×0.250.034×0.5×0.21.3×2.5+0.7×2.5 1.26×0.6+1.26×0.4 102×0.5545.计算.(怎样简便就怎么计算)13.38+0.98=7.02﹣2.98 6.57﹣(0.68﹣0.39+0.32)13.8÷(1.38×0.2)30.7﹣0.12×2﹣0.76 7.8×1.0118.4﹣6.5+1.6+3.5 7.8÷0.6+7.8÷0.412.13+7.5﹣1.13+2.850.125×8.89.4×3.2+6×0.32 9.6×3.6+7.2×0.2.46.计算下面各题,能简算得要简算.96÷(100×0.48) 3.6÷(1.2+0.5)×6(967﹣31)÷(17+48)72×10.1+27×10.1.47.用自己喜欢的方法计算.3.4×7.8÷3.9 54÷(6.86+3.94)48.用简便方法计算17.5×2.3﹣7.5×2.3 1.25×11×4×0.8 0.486+0.01+3.9945.55﹣(6.82+15.55) 3.2×99+3.24.8×39+61×4.82.5×56+4.5×56(31.6﹣11.7)÷2.5÷4 3.6×0.9+3.6×0.1 49.计算下列各题.(能简算的要简算)7.5﹣2.4÷0.8×2.512.5×17+83×12.5399×2.525÷(2.5÷0.4)3.25×67+5.75×67+67 230÷2.5×7.5 6.3+0.84+3.7+8.16100﹣(2.72+10.8)÷0.250.脱式计算0.25×3.25×4 6.72+3.2÷2.521.36÷0.4﹣23.40.8×4.5+1.2×4.5.小数除法脱式运算+简算260道参考答案与试题解析一.计算题(共50小题)1.【解答】解:(1)32×12.5×0.25=4×8×12.5×0.25=(4×0.25)×(8×12.5)=1×100=100(2)6.1×4.2+5.8×6.1=6.1×(4.2+5.8)=6.1×10=61(3)1.7÷2.5÷0.4=1.7÷(2.5×0.4)=1.7÷1=1.7(4)16.1﹣4.2﹣5.8=16.1﹣(4.2+5.8)=16.1﹣10=6.1 2.【解答】解:(1)(0.6×0.8+0.12)÷1.2=0.6÷1.2=0.5答:商是0.5.(2)(14.81+5.19)×(14.81﹣5.19)=20×9.62=192.4答:积是192.4.(3)[(2.7+4.5)÷12]×0.3=[7.2÷12]×0.3=0.6×0.3=0.18答:积是0.18.3.【解答】解:①4.8÷(1.2÷0.5)=4.8÷2.4=2②12.8﹣12.8÷5=12.8﹣2.56=10.24③71.4÷(7×6)=71.4÷7÷6=10.2÷6=1.74.【解答】解:①0.65×101﹣0.65 =0.65×(101﹣1)=0.65×100=65②12.6﹣3.25+6.75=12.6+(6.75﹣3.25)=12.6+3.5=16.1③6.35÷0.2÷0.5=6.35÷(0.2×0.5)=6.35÷0.1=63.5④5.7×1.2÷19 =5.7÷19×1.2=0.3×1.2=0.36⑤1.25×3.63×0.8=(1.25×0.8)×3.63=1×3.63=3.63 5.【解答】解:①0.11×1.8+8.2×0.11=0.11×(1.8+8.2)=0.11×10=1.1②3.5﹣3.5×0.98=3.5×(1﹣0.98)=3.5×0.02=0.07③0.75×18÷0.15=0.75÷0.15×18=5×18=90④0.25×4.78×8=0.25×8×4.78=2×4.78=9.56 6.【解答】解:①17.3÷0.125÷8 =17.3÷(0.125×8)=17.3÷1=17.3 ②14.72×0.7+5.28×0.7=(14.72+5.28)×0.7=20×0.7=14③3.5÷0.56 =(3.5÷0.7)÷(0.56÷0.7)=5÷8=0.625④8.5×9.9+0.82=8.5×(10﹣0.1)+0.82=8.5×10﹣8.5×0.1+0.82=85﹣0.85+0.82=85﹣(0.85﹣0.82)=85﹣0.03=84.97 7.【解答】解:(1)38.75﹣(24.5+8.75)=38.75﹣24.5﹣8.75=38.75﹣8.75﹣24.5=30﹣24.5=5.5;(2)0.4×2.32×0.25=0.4×0.25×2.32=0.1×2.32=0.232;(3)0.75×101=0.75×(100+1)=0.75×100+0.75×1=75+0.75=75.75;(4)4.2﹣3.2×0.9=4.2﹣2.88=1.32;(5)7.56×99+7.56=7.56×(99+1)=7.56×100=756;(6)70.3﹣17.48÷7.6=70.3﹣2.3=68;(7)3.64÷5.2×23.3=0.7×23.3=16.31;(8)21.8÷0.8﹣1.2×5=27.25﹣6=21.25;(9)45÷(5.25÷0.25)=45÷21=;(10)16.5×101﹣16.5=16.5×(101﹣1)=16.5×100=1650;(11)0.96÷0.3×14=3.2×14=44.8;(12)1.25×4×2.5×8=(1.25×8)×(4×2.5)=10×10=100;(13)36.45÷(0.82+3.4×0.2)=36.45÷(0.82+0.68)=36.45÷1.5=24.3;(14)9.07﹣2.64÷0.4=9.07﹣6.6=2.47;(15)1.5×101=1.5×(100+1)=1.5×100+1.5×1=150+1.5=151.5;(16)12.6×7.5+8.3=94.5+8.3=102.8;(17)13.6×0.85﹣3.6×0.85=(13.6﹣3.6)×0.85=10×0.85=8.5;(18)104×8.5=(100+4)×8.5=100×8.5+4×8.5=850+34=884;(19)86.4÷6.4﹣0.4=13.5﹣0.4=13.1;(20)0.25×6.2×0.4=0.25×0.4×6.2=0.1×6.2=0.62;(21)23×6.5+17×6.5=(23+17)×6.5=40×6.5=260;(22)36÷0.4×0.25=90×0.25=22.5;(23)(24.6﹣18.1)×3.4=6.5×3.4=22.1;(24)7.6×9.9+7.6×0.1=7.6×(9.9+0.1)=7.6×10=76;(25)13.6×0.8×12.5=13.6×(0.8×12.5)=13.6×10=136;(26)23.9×8.5﹣3.9×8.5=(23.9﹣3.9)×8.5=20×8.5=170;(27)(2.55+9.6÷16)÷0.42=(2.55+0.6)÷0.42=3.15÷0.42=7.5;(28)9.2÷0.25÷4=9.2÷(0.25×4)=9.2÷1=9.2.8.【解答】解:(1)0.75×4×0.25×4=(0.75×4)×(0.25×4)=3×1=3(2)9.6+9.9×99=9.6+9.9×(100﹣1)=9.6+9.9×100﹣9.9=9.6+990﹣9.9=989.7(3)15.58÷8.2﹣0.72=1.9﹣0.72=1.18(4)4.536÷0.8÷14=5.67÷14=0.405(5)2.8×3.6+1.4×2.8=2.8×(3.6+1.4)=2.8×5=14(6)6.3×10.1=6.3×(10+0.1)=6.3×10+6.3×0.1=63+0.63=63.63 9.【解答】解:(1)4.2×7.8+2.2×4.2 =4.2×(7.8+2.2 )=4.2×10=42(2)9.5×101=9.5×(100+1)=9.5×100+9.5=950+9.5=959.5(3)(8×3.82)×1.25 =(8×1.25)×3.82=10×3.82=38.2(4)0.125×72=0.125×8×9=1×9=9(5)0.6×3.9×0.8 =2.34×0.8=1.872(6)42×0.39+4.2×6.1=42×0.39+42×0.61=42×(0.39+0.61)=42×1=42 10.【解答】解:(1)0.25×1.25×16=0.25×1.25×(2×8)=(0.25×2)×(1.25×8)=0.5×10=5(2)18.9﹣18.9÷1.4=18.9﹣13.5=5.4(3)8.37×1.2﹣8.37×0.2=8.37×(1.2﹣0.2)=8.37×1=8.37(4)43×11.8+5.7×118=43×11.8+57×11.8=(43+57)×11.8=100×11.8=1180 11.【解答】解:(1)6.2+5.18+2.8 =6.2+2.8+5.18 =9+5.18=14.18 (2)15.35﹣(5.35+7.2)=15.35﹣5.35﹣7.2=10﹣7.2=2.8(3)3.63﹣1.25+17.37﹣8.75=(3.63+17.37)﹣(1.25+8.75)=21﹣10=11 (4)51.72﹣8.66﹣1.34=51.72﹣(8.66+1.34)=51.72﹣10=41.72 12.【解答】解:(1)0.7×101﹣0.7 =0.7×(101﹣1)=0.7×100=70(2)0.125×4.7×8=0.125×8×4.7=1×4.7=4.7(3)12.9﹣1.68﹣2.32 =12.9﹣(1.68+2.32)=12.9﹣4=8.9(4)567÷20÷5=567÷(20×5)=567÷100=5.67 13.【解答】解:①20.16÷7.2+9.8 =2.8+9.8=12.6;②6.2×2.7+6.5×7.3 =16.74+47.45=64.19;③32.8+9.6+7.2=9.6+(32.8+7.2)=9.6+40=49.6.14.【解答】解:(1)15.89﹣(5.89+6.98)=15.89﹣5.89﹣6.98=10﹣6.98=3.02;(2)0.25×13.7×0.4=0.25×0.4×13.7=0.1×13.7=1.37;(3)32.7×28+7.3×28 =(32.7+7.3)×28=40×28=1120;(4)15×9.4﹣42=141﹣42=99;(5)4.9+12.87﹣5.38=17.77﹣5.38=12.39;(6)0.05×0.7×20×1.7=0.05×20×0.7×1.7=1×0.7×1.7=0.7×1.7=1.19.15.【解答】解:(1)5.04×28=(5+0.04)×28=5×28+0.04×28=140+1.12=141.12;(2)(15.4﹣7.8)×3.5 =7.6×3.5 =26.6;(3)3.2×4.6+3.2×5.4=3.2×(4.6+5.4)=3.2×10=32;(4)0.25×17.4×4=0.25×4×17.4=1×17.4=17.4;(5)20﹣6.72﹣3.28=20﹣( 6.72+3.28)=20﹣10=10;(6)8.33+7.45+1.67+2.55=8.33+1.67+7.45+2.55=(8.33+1.67)+(7.45+2.55)=10+10=20.16.【解答】解:(1)0.2×0.6×0.5×4 =(0.2×0.5)×(0.6×4)=0.1×2.4=0.24;(2)(7.5﹣2.3×0.4)÷0.01=(7.5﹣0.92)÷0.01=6.58÷0.01=658;(3)1.2×0.25+2.8×0.25 =(1.2+2.8)×0.25=4×0.25=1;(4)178.8÷(26.4﹣5.6)=178.8÷20.8=.17.【解答】解:(1)3.6﹣1.28+3.09=2.32+3.09=5.41(2)3.82+2.9+0.18+9.1 =(3.82+0.18)+(9.1+2.9)=4+12=16(3)9.43﹣(6.28﹣1.57)=9.43+1.57﹣6.28=11﹣6.28=4.72(4)21.32﹣(6.32+8.3)=21.32﹣6.32﹣8.3=15﹣8.3=6.7(5)13.75﹣(3.75+6.48)=13.75﹣3.75﹣6.48=10﹣6.48=3.52(6)15﹣7.35﹣2.65=15﹣(7.35+2.65)=15﹣10=5 18.【解答】解:①19.81﹣2.68﹣8.32=19.81﹣(2.68+8.32)=19.81﹣11=8.81②5.6+6.6﹣5.6+6.6=(5.6﹣5.6)+(6.6+6.6)=0+13.2=13.2③0.81×27+0.19×27=27×(0.81+0.19)=27×1=27④101×0.19﹣0.19=(101﹣1)×0.19=100×0.19=19 19.【解答】解:(1)9.08﹣1.76﹣4.24 =9.08﹣(1.76+4.24)=9.08﹣6=3.08;(2)18.38﹣(5.38+1.8)﹣8.2=18.38﹣7.18﹣8.2=11.2﹣8.2=3;(3)17.45﹣(8.76﹣6.55)=17.45﹣8.76+6.55=17.45+6.55﹣8.76=24﹣8.76=15.24;(4)12.87+3.98﹣3.87=12.87﹣3.87+3.98=9+3.98=12.98.20.【解答】解:①10.8÷(3.94+6.86)×0.8=10.8÷10.8×0.8=1×0.8=0.8②0.65×201 =0.65×(200+1)=0.65×200+0.65×1=130+0.65=130.65③12.5×3.9×0.8=12.5×0.8×3.9=10×3.9=39④39.8×0.25×4 =39.8×(0.25×4)=39.8×1=39.8⑤37.6×8+37.6×2=37.6×(8+2)=37.6×10=376⑥0.78×99+0.78=0.78×(99+1)=0.78×100=78 21.【解答】解:(1)21.8﹣7.22﹣2.78=21.8﹣(7.22+2.78)=21.8﹣10=11.8(2)9﹣0.24÷1.6×1.1=9﹣0.15×1.1=9﹣0.165=8.835(3)9.12+9.12×9﹣6.02=9.12×(1+9)﹣6.02=9.12×10﹣6.02=91.2﹣6.02=85.18(4)45.2×66.7+66.7×53.8+66.7=(45.2+53.8+1)×66.7=100×66.7=6670(5)0.25×0.8×0.125×0.4=(0.25×0.4)×(0.125×0.8)=0.1×0.1=0.01(6)12.75÷[14.6﹣(1.3+8.2)]=12.75÷[14.6﹣9.5]=12.75÷5.1=2.5(7)0.125×36×(4÷0.5)÷36=0.125×(4÷0.5)×(36÷36)=0.125×8×1=1(8)[(6.1﹣4.6)×0.8﹣1]×0.36=[1.5×0.8﹣1]×0.36=[1.2﹣1]×0.36=0.2×0.36=0.072(9)15.6﹣(4.1+0.2+6.86÷0.7)=15.6﹣(4.1+0.2+9.8)=15.5﹣(4.1+10)=15.5﹣14.1=1.4(10)[5﹣(1﹣1.2×0.8)]÷4=[5﹣(1﹣0.96)]÷4=[5﹣0.04]÷4=4.96÷4=1.24(11)1÷0.25+0.4×0.6=4+0.24=4.24(12)13.6×3﹣40.6÷2=40.8﹣20.3=20.5(13)25.8+10.5÷(5﹣3.5)=25.8+10.5÷1.5=25.8+7=32.8(14)1.42﹣0.36÷6×0.6=1.42﹣0.36=1.07(15)49.5×0.2﹣2.07÷23=9.9﹣0.09=9.81(16)6.7+3.3÷4.4+5.6=6.7+0.75+5.6=7.45+5.6=13.05 22.【解答】解:①50×(0.8+0.4)=50×0.8+50×0.4=40+20=60②7.34×2.1+7.34×6.8+7.34×1.1=7.34×(2.1+6.8+1.1)=7.34×10=73.4③20.5÷1.25÷0.8=20.5÷(1.25×0.8)=20.5÷1=20.5 ④9.88×9+9.88=9.88×(9+1)=9.88×10=98.8 23.【解答】解:(1)12.6÷(1.02+3.18)=12.6÷4.2=3;(2)5.7×6.9+4.3×6.9=(5.7+4.3)×6.9=10×6.9=69;(3)(0.81+2.7)÷0.9=3.51÷0.9=3.9;(4)[(8.4﹣7.9)÷0.25]×1.2=[0.5÷0.25]×1.2=2×1.2=2.4.24.【解答】解:(1)25×1.25×32 =25×1.25×8×4=(25×4)×(1.25×8)=100×10=1000(2)(+)×35=×35+×35=10+7=17(3)78×=(79﹣1)×=79×﹣=3﹣=2(4)÷+=÷=25.【解答】解:(1)1.6×3.9×1.25=0.8×2×3.9×1.25=(0.8×1.25)×(2×3.9)=1×7.8=7.8(2)4.87×2.34+48.7×0.266=4.87×2.34+4.87×2.66=4.87×(2.34+2.66)=4.87×5=24.35(3)0.49×9.9 =0.49×(10﹣0.1)=0.49×10﹣0.49×0.1=4.9﹣0.049=4.851(4)0.05×0.7×20×1.7=(0.05×20)×(0.7×1.7)=1×1.19=1.19(5)2.5×3.2×12.5 =2.5×0.4×8×12.5 =(2.5×0.4)×(8×12.5)=1×100=100(6)3.95×7.6+3.95×3.4﹣3.95=3.95×(7.6+3.4﹣1)=3.95×10=39.5 26.【解答】解:(1)7.8×6.9+2.2×6.9=(7.8+2.2)×6.9=10×6.9=69(2)2.36×2.5×4=2.36×(2.5×4)=2.36×10=23.6(3)102×0.45=(100+2)×0.45=100×0.45+2×0.45=45+0.9=45.9(4)4.19×99+4.19=4.19×(99+1)=4.19×100=419(5)21.36÷0.8﹣12.9=26.7﹣12.9=13.8(6)3.2÷0.8×0.26=4×0.26=1.04 27.【解答】解:(1)6.33×101﹣6.33=6.33×(101﹣1)=6.33×100=633;(2)1.6×55.4﹣55.4×0.6=(1.6﹣0.6)×55.4=1×55.4=55.4;(3)17.68÷5.2+2.7×1.5=3.4+4.05=7.45;(4)(1.1﹣0.78)×(2.7﹣1.95)=0.32×0.75=0.24;(5)35.6﹣5×1.73=35.6﹣8.65=26.95;(6)15÷0.2÷2.5=15÷(0.2×2.5)=15÷0.5=30.28.【解答】解:(1)2.5×1.37×0.4=2.5×0.4×1.37=1×1.37=1.37;(2)4.8×0.25×25=(4×4×0.3)×0.25×25=(4×0.25)×(4×25)×0.3=1×100×0.3=30;(3)0.89×4.8+0.89×5.2=0.89×(4.8+5.2)=0.89×10=8.9;(4)101×0.78×20=101×(0.78×20)=101×15.6=(100+1)×15.6=100×15.6+1×15.6=1560+15.6=1575.6;(5)8.8×1.25×15=(8×1.1)×1.25×15=(8×1.25)×(1.1×15)=10×16.5=165;(6)4.3×0.8×5=4.3×(0.8×5)=4.3×4=17.2.29.【解答】解:(1)44.28÷0.9÷4.1=49.2÷4.1=12;(2)0.25×0.39×4=(0.25×4)×0.39=1×0.39=0.39;(3)7.6+7.6×99=7.6×(1+99)=7.6×100=760;(4)9.07﹣22.78÷3.4=9.07﹣6.7=2.37;(5)4.8×99+4.8=4.8×(99+1)=4.8×100=480;(6)6.3×10.1=6.3×(10+0.1)=6.3×10+6.3×0.1=63+0.63=63.63.30.【解答】解:(1)5.8+3.8×0.25=5.8+0.95=6.75(2)1.7×(4.65﹣3.87)=1.7×0.78=1.326(3)1.25×4.3×0.8=1.25×0.8×4.3=1×4.3=4.3(4)4.5×102=4.5×(100+2)=4.5×100+4.5×2=450+9=459(5)0.54×101﹣0.54=0.54×(101﹣1)=0.54×100=54(6)3.4×2.5+6.6×2.5=(3.4+6.6)×2.5=10×2.5=25 31.【解答】解:①0.45×12×0.2=0.45×0.2×12=0.09×12=1.08 ②6.2×2.1﹣2.1 =2.1×(6.2﹣1)=2.1×5.2=10.92 ③0.9×0.8×100=0.72×100=72④2.8﹣2.8×0.15 =2.8×(1﹣0.15)=2.8×0.85=2.38 ⑤2.8×1.43+0.57 =4.004+0.57=4.574⑥72×0.81+10.3=58.32+10.3=68.62⑦10﹣6.06+8.5=3.94+8.5=12.44 ⑧6×0.25×1.8 =1.5×1.8=2.7⑨7.06×2.4﹣5.8 =16.944﹣5.8=11.144 32.【解答】解:(1)0.25×9.87×4 =0.25×4×9.87=1×9.87=9.87;(2)36.2×1.8+13.8×1.8 =(36.2+13.8)×1.8=50×1.8=90;(3)0.125×2.3×8=0.125×8×2.3=1×2.3=2.3;(4)0.73×102 =0.73×(100+2)=0.73×100+0.73×2=73+1.46=74.46;(5)(6.8+2.6)×5 =6.8×5+2.6×5=34+13=47;(6)0.23×98=0.23×(100﹣2)=0.23×100﹣0.23×2=23﹣0.46=22.54.33.【解答】解:(1)12.5×32×2.5 =12.5×4×8×2.5=(12.5×8)×(2.5×4)=100×10=1000;(2)6.8×9.9 =6.8×(10﹣0.1)=6.8×10﹣6.8×0.1=68﹣0.68=67.32;(3)7.2÷[1.8×(3.4﹣2.9)]=7.2÷[1.8×0.5]=7.2÷0.9=8.34.【解答】解:(1)3.4×9+3.4=30.6+3.4=34;(2)6.4÷0.8﹣1.5×4=8﹣6=2;(3)3.78÷0.25÷4=3.78÷(0.25×4)=3.78÷1=3.78;(4)17÷[(1.2+0.5)×5]=17÷[1.7×5]=17÷8.5=2.35.【解答】解:(1)2.5×1.25×8×0.4 =(2.5×0.4)×(1.25×8)=1×10=10;(2)12.8×1.7+87.2×1.7 =(12.8+87.2)×1.7=100×1.7=170;(3)100﹣4.35﹣5.65=100﹣(4.35+5.65)=100﹣10=90.36.【解答】解:(1)4+7.6×15 =4+114=118;(2)26.08÷0.25÷4=26.08÷(0.25×4)=26.08÷1=26.08;(3)19.7+(80.5÷35×0.2)=19.7+(2.3×0.2)=19.7+0.46=20.16.37.【解答】解:(1)1.25×2.25×0.8=1.25×0.8×2.25=1×2.25=2.25;(2)9.7×99+9.7=9.7×(99+1)=9.7×100=970;(3)4.8×7.8+78×0.52=4.8×7.8+7.8×5.2=(4.8+5.2)×7.8=10×7.8=78;(4)3.65×10.1=3.65×(10+0.1)=3.65×10+3.65×0.1=36.5+0.365=36.865.38.【解答】解:①12.36﹣6.49﹣3.51=12.36﹣(6.49+3.51)=12.36﹣10=2.36;②8.5×3.8+8.5×6.2=8.5×(3.8+6.2)=8.5×10=85;③17.3×0.25×8=17.3×(0.25×8)=17.3×2=34.6;④15.32﹣1.8×5﹣3.46=15.32﹣9﹣3.46=6.32﹣3.46=2.86;⑤199×2.6=(200﹣1)×2.6=200×2.6﹣1×2.6=520﹣2.6=517.4;⑥3.6÷[(1.3+0.6)×5]=3.6÷[1.9×5]=3.6÷9.5=.39.【解答】解:(1)8.5+6.85﹣6.35 =8.5+(6.85﹣6.35)=8.5+0.5=9;(2)3.9+0.1﹣3.9+0.1 =(3.9﹣3.9)+(0.1+0.1)=0+0.2=0.2;(3)12.6﹣(3.75+5.08)=12.6﹣8.83=3.77.40.【解答】解:(1)6.09﹣9.13÷8.3=6.09﹣1.1=4.99(2)3.84×9.6+0.96×61.6 =(3.84+6.16)×9.6=10×9.6=96(3)4.86×99=4.86×(100﹣1)=4.86×100﹣4.86=486﹣4.86=481.14(4)5.68×4+4.32÷0.25 =5.68×4+4.32×4=(5.68+4.32)×4=10×4=40(5)6.4×4.5+3.6×4.5=(6.4+3.6)×4.5=10×4.5=4541.【解答】解:①10.5+61×18=10.5+1098=1108.5 ②(3.14+12.6)÷8=15.74÷8=1.9675③4.5÷(15÷3)=4.5÷5=0.9④75+448÷4×19=75+112×19=75+2128=2203 42.【解答】解:(1)(18.5×3.8+3.8×2.5)÷0.19 =3.8×(18.5+2.5)÷0.19 =3.8×21÷0.19=3.8÷0.19×21=200×21=4200(2)[32﹣(7.25+0.75×8)]÷50=[32﹣(7.25+6)]÷50=[32﹣13.25]÷50=18.75÷50=0.375 43.【解答】解:①25.32﹣(3.4﹣1.2)=25.32﹣2.2=23.12②12﹣0.62﹣4.38=12﹣(0.62+4.38)=12﹣5=744.【解答】解:(1)5.12+2.54+4.88=5.12+4.88+2.54=10+2.54=12.54;(2)12.5×17.8×0.8=12.5×0.8×17.8=10×17.8=178;(3)0.24×0.48×4=0.1152×4=0.4608;(4)9.9×2.5=(10﹣0.1)×2.5=10×2.5﹣0.1×2.5=25﹣0.25=24.75;(5)9.4×5.8+10.6×5.8=(9.4+10.6)×5.8=20×5.8=116;(6)0.66×101=0.66×(100+1)=0.66×100+0.66×1=66+0.66=66.66;(7)4.8×0.25=(1.2×4)×0.25=1.2×(4×0.25)=1.2×1=1.2;(8)2.33×0.5×4 =2.33×(0.5×4)=2.33×2=4.66;(9)1.3×2.5+0.7×2.5=(1.3+0.7)×2.5=2×2.5=5;(10)1.26×0.6+1.26×0.4=1.26×(0.6+0.4)=1.26×1=1.26;(11)102×0.55=(100+2)×0.55=100×0.55+2×0.55=55+1.1=56.1;(12)0.034×0.5×0.2=0.034×(0.5×0.2)=0.034×0.1=0.0034.45.【解答】解:(1)13.38+0.98=13.38+(1﹣0.02)=13.38+1﹣0.02=14.38﹣0.02=14.36;(2)7.02﹣2.98 =7.02﹣(3﹣0.02)=7.02﹣3+0.02 =4.02+0.02=4.04;(3)6.57﹣(0.68﹣0.39+0.32)=6.57﹣(0.68+0.32﹣0.39)=6.57﹣(1﹣0.39)=6.57﹣0.61=5.96;(4)13.8÷(1.38×0.2)=13.8÷1.38÷0.2=10÷0.2=50;(5)30.7﹣0.12×2﹣0.76 =30.7﹣0.24﹣0.76=30.7﹣(0.24+0.76)=30.7﹣1=29.7;(6)7.8×1.01=7.8×(1+0.01)=7.8×1+7.8×0.01=7.8+0.078=7.878;(7)18.4﹣6.5+1.6+3.5 =(18.4+1.6)﹣(6.5﹣3.5)=20﹣3=17;(8)7.8÷0.6+7.8÷0.4=13+19.5=32.5;(9)12.13+7.5﹣1.13+2.85=(12.13﹣1.13)+(7.5+2.85)=11﹣10.35=0.65;(10)0.125×8.8=0.125×(8+0.8)=0.125×8+0.125×0.8=1+0.1=1.1;(11)9.4×3.2+6×0.32 =9.4×3.2+0.6×3.2=(9.4+0.6)×3.2=10×3.2=32;(12)9.6×3.6+7.2×0.2=9.6×3.6+3.6×2×0.2=9.6×3.6+3.6×0.4=(9.6+0.4)×3.6=10×3.6=36.46.【解答】解:(1)96÷(100×0.48)=96÷48=2;(2)3.6÷(1.2+0.5)×6=3.6÷1.7×6=×6=;(3)(967﹣31)÷(17+48)=936÷65=14.4;(4)72×10.1+27×10.1=(72+27)×10.1=99×10.1=99×(10+0.1)=99×10+99×0.1=990+9.9=999.9.47.【解答】解:(1)3.4×7.8÷3.9=26.52÷3.9=6.8;(2)54÷(3.94+6.86)=54÷10.8=5.48.【解答】解:①0.486+0.01+3.99 =0.486+(0.01+3.99)=0.486+4=4.486 ②17.5×2.3﹣7.5×2.3 =2.3×(17.5﹣7.5)=2.3×10=23 ③1.25×11×4×0.8=(1.25×0.8)×(11×4)=1×44=44④4.8×39+61×4.8=4.8×(39+61)=4.8×100=480⑤45.55﹣(6.82+15.55)=45.55﹣6.82﹣15.55=45.55﹣15.55﹣6.82=30﹣6.82=23.18⑥3.2×99+3.2=3.2×(99+1)=3.2×100=320⑦2.5×56+4.5×56 =56×(2.5+4.5)=56×7=392⑧(31.6﹣11.7)÷2.5÷4 =19.9÷(2.5×4)=19.9÷10=1.99⑨3.6×0.9+3.6×0.1=3.6×(0.9+0.1)=3.6×1=3.6 49.【解答】解:(1)7.5﹣2.4÷0.8×2.5 =7.5﹣3×2.5=7.5﹣7.5=0;(2)12.5×17+83×12.5=12.5×(17+83)=12.5×100=1250;(3)399×2.5 =(400﹣1)×2.5=400×2.5﹣2.5=1000﹣2.5=997.25;(4)25÷(2.5÷0.4)=25÷2.5×0.4=10×0.4=4;(5)3.25×67+5.75×67+67 =(3.25+5.75+1)×67=10×67=670;(6)230÷2.5×7.5=92×7.5=690;(7)6.3+0.84+3.7+8.16=(6.3+3.7)+(0.84+8.16)=10+9=19;(8)100﹣(2.72+10.8)÷0.2=100﹣13.52÷0.2=100﹣67.6=32.4.50.【解答】解:(1)0.25×3.25×4=0.25×4×3.25=1×3.25=3.25(2)6.72+3.2÷2.5=6.72+1.28=8(3)21.36÷0.4﹣23.4=53.4﹣23.4=30(4)0.8×4.5+1.2×4.5=(0.8+1.2)×4.5=2×4.5=9。

小数除法脱式运算+简算260道含答案,推荐文档

小数除法脱式运算+简算260道含答案,推荐文档

小数除法脱式运算+简算260道一 .计算题(共50小题)1.用你喜欢的方法计算.32 X 12.5X 0.25 6.1 X 4.2+5.8X 6.1 1.7- 2.5- 0.4 16.1 - 4.2 - 5.8.3.脱式计算4.8- (1.2- 0.5) 12.8 - 12.8-5 71.4- (7 X 6)4.用你喜欢的方法计算0.65 X 101 - 0.65 12.6-3.25+6.756.35-0.2-0.5 5.7X 1.2- 19 1.25X 3.63X 0.8.5.我能用喜欢的方法计算下面各题.0.11 X 1.8+8.2X 0.11 3.5— 3.5X 0.98 0.75X 18-0.15 0.25X 4.78X 8.6 .能简算的要简算.17.3-0.125-8 14.72X 0.7+5.28X 0.73.5-0.56 8.5X 9.9+0.82.7.递等式计算,有简便运算的用简便方法38.75 - (24.5+8.75) 0.4X 2.32X 0.25 0.75X 101 4.2- 3.2X 0.97.56 X70.3- 17.48-7.6 3.64-5.2 X 23.3 21.8-0.8 - 1.2X 5 99+7.5645 - (5.25-0.25) 16.5X 101 - 16.5 0.96-0.3X 14 1.25X 4X 2.5X 8 36.45- (0.82+3.4X 0.2) 9.07-2.64-0.4 1.5X 101 12.6X 7.5+8.3 13.6X 0.85- 3.6X 0.85 104X 8.5 86.4-6.4 - 0.4 0.25X 6.2X 0.423 X 6.5+17 X36+0.4 X 0.25 (24.6— 18.1) X3.4 7.6X 9.9+7.6X 0.1 6.513.6X 0.8X 12.5 23.9X 8.5 - 3.9X 8.5 (2.55+9.6- 16) -0.42 9.2- 0.25-40.75X 4X 0.25X 49. 脱式计算(能简算的要用简算)10. 脱式计算,能简算的要简算 0.25 X 1.25X 1618.9- 18.9- 1.4 8.37X 1.2 - 8.37 X 0.243 X 11.8+5.7X 118.11. 用简便方法计算. 6.2+5.18+2.815.35- (5.35+7.2)12. 脱式计算,能简算的要简算. 0.7X 101 - 0.70.125X 4.95X 83.63 - 1.25+17.37 - 8.7551.72 - 8.66 - 1.34.4.536- 0.8+ 142.8 X3.6+1.4X 2.8 6.3X 10.1.4.2X 7.8+2.2X 4.29.5X 101(8 X 3.82) X1.250.125X 720.6X 3.9X 0.8 42 X 0.39+4.2X 6.112.9- 1.68 - 2.32 567- 20- 5.20.16- 7.2+9.814. 脱式计算:能简算的要简算16. 脱式计算.1.2X 0.25+2.8 X 0.25178.8- (26.4— 5.6)0.2X 0.6X 0.5X 4(7.5— 2.3X 0.4) -0.0115.89- (5.89+6.98)0.25X 13.7X 0.432.7X 28+7.3X 2815X 9.4 - 42 4.9+12.87-5.38 0.05X 0.7X 20 X 1.7.15. 计算下面各题, 能简算的要简算.5.04 X 28(15.4— 7.8) X 3.53.2X4.6+3.2X5.40.25 X 17.4X 420 - 6.72 - 3.28 8.33+7.45+1.67+2.553.6- 1.28+3.093.82+2.9+0.18+9.1 9.43 - (6.28 —1.57)21.32- (6.32+8.3) 13.75- (3.75+6.48) 15 - 7.35- 2.6518. 混合运算,能简便就简便19.81 - 2.68—8.32 5.6+6.6— 5.6+6.6 0.81 X 27+0.19X 27 101 X 0.19 -0.19.19. 用简便方法计算9.08 - 1.76— 4.24 18.38 - (5.38+1.8) - 8.2 17.45- (8.76— 6.55) 12.87+3.98- 3.87.20. 脱式计算,能简便的用简便方法计算.10.8- (3.94+6.86) X 0.8 0.65X 201 12.5X 3.9X 0.839.8 X 0.25X 4 37.6X 8+37.6X 2 0.78 X 99+0.78.21.8 -7.22 - 2.78 9- 0.24- 1.6X 1.1 9.12+9.12X 9 -6.02 45.2X 66.7+66.7X 53.8+66.7 0.25X 0.8X 0.125X 0.4 12.75- [14.6 - (1.3+8.2)]0.125X 36X (4- 0.5) -36 [ (6.1 — 4.6) X 0.8 - 1] X 0.36 15.6 - (4.1+0.2+6.86-0.7)[5- (1- 1.2X 0.8) ] - 4 1-0.25+0.4X 0.6 13.6X 3-40.6- 225.8+10.5- (5 - 3.5) 1.42 - 0.36- 6 X 0.6 49.5 X 0.2 - 2.07+ 23 6.7+3.3-4.4+5.622. 计算下面各题(能简算的要简算)50X (0.8+0.4) 7.34X 2.1+7.34X 6.8+7.34X 1.120.5- 1.25+ 0.8 9.88X 9+9.88.23. 计算下列各题(能用简便算法的要用简便算法).12.6- (1.02+3.18) 5.7X 6.9+4.3X 6.9(0.81+2.7) -0.9 [ (8.4— 7.9) - 0.25] X 1.2.25. 能简算的用简便方法计算.(写出主要简便过程,无过程不得分)1.6X 3.9X 1.25 4.87X2.34+48.7 X 0.2662.5X3.2X 12.5 3.95X 7.6+3.95X 3.4 - 3.95.26. 计算下面各题,能简算的要简算7.8X 6.9+2.2X 6.9 2.36X 2.5X 4 102X 0.454.19X 99+4.19 21.36-0.8- 12.9 3.2+ 0.8X 0.2627. 计算(能简算的要简算).6.33 X 101 - 6.33 1.6X 55.4 - 55.4X 0.6 17.68-5.2+2.7X 1.5 (1.1— 0.78) X ( 2.7— 1.95) 35.6 - 5X 1.73 15-0.2-2.528. 脱式计算(能简算的要简算)2.5X 1.37X 0.4 4.8X 0.25X 25 0.89X 4.8+0.89X 5.2101X 0.78X 20 8.8X 1.25X 15 4.3X 0.8X 529. 计算下面各题,能简算的要简算.44.28- 0.9-4.1 0.25X 0.39X 4 7.6+7.6 X 999.07 - 22.78-3.4 4.8X 99+4.8 30.下面各题,能简算的就要简算. 5.8+3.8X 0.25 1.7X (4.65 — 3.87) 6.3X 10.11.25X 4.3X 0.84.5X 102 0.54X 101 - 0.54 3.4X 2.5+6.6X 2.5.31. 计算下列各题. 0.45X 12X 0.2 2.8-2.8X 0.15 10-6.06+8.5 32. 用简便方法计算. 0.25 X 9.87X 4 6.2X 2.1 - 2.1 0.9X 0.8X 1000.73 X 1022.8X 1.43+0.57 72X 0.81+10.36X 0.25X 1.8 7.06X 2.4-5.836.2X 1.8+13.8X 1.8 0.125X 2.3X 8(6.8+2.6) X 5 0.23X 98.33.能用简便方法的用简便方法计算 12.5X 32X 2.5 6.8 X 9.9第8页(共19页)7.2- [1.8X (3.4 — 2.9)].34. 用你喜欢的方法计算.3.4X 9+3.4 6.4-0.8 - 1.5X 4 3.78- 0.25-4 17-[ (1.2+0.5) X 5].35. 用你喜欢的方法计算2.5X 1.25X 8X 0.4 12.8X 1.7+87.2X 1.7 100 - 4.35- 5.65.36. 用递等式计算(能简算的要简算).4+7.6X 15 26.08+ 0.25-4 19.7+ (80.5-35 X 0.2)37. 计算,能简算的要简算.1.25X2.25X 0.8 9.7X 99+9.7 4.8X 7.8+78X 0.523.65X 10.1.38 .计算下面各题.(能简算的用简便算法)① 12.36-6.49- 3.51 ②8.5X 3.8+8.5X 6.2 ③ 17.3X 0.25X 8④ 15.32- 1.8X5 - 3.46 ⑤ 199X 2.6 ⑥3.6-[ (1.3+0.6) X 5]39. 计算8.5+6.85 - 6.35 3.9+0.1 - 3.9+0.1 12.6- (3.75+5.08)40. 计算,能简算的要简算6.09 - 9.13-8.3 3.84X 9.6+0.96X 61.6 4.86X 995.68 X 4+4.32- 0.256.4X 4.5+3.6X 4.5.41. 脱式计算.10.5+61 X 18 (3.14+12.6) -8 4.5- (15-3) 75+448-4X 19.42. 计算:(18.5X 3.8+3.8X 2.5) -0.19 [32 - ( 7.25+0.75X 8) ] - 50.43. 脱式计算,能简算的就简算:25.32- (3.4— 1.2) 12- 0.62- 4.38.44. 用简便方法计算下面各题.5.12+2.54+4.88 12.5X 17.8X 0.8 0.24X 0.48X 4 9.9X 2.59.4X 5.8+10.6X 5.8 0.66X 101 4.8X 0.25 2.33X 0.5X 4 1.3X 2.5+0.7X 2.5 1.26X 0.6+1.26X 0.4 102X 0.55 0.034X 0.5X 0.245. 计算.(怎样简便就怎么计算)13.38+0.98= 7.02— 2.98 6.57 - (0.68 — 0.39+0.32)13.8- (1.38X0.2) 30.7-0.12X 2-0.76 7.8X 1.0118.4-6.5+1.6+3.5 7.8-0.6+7.8+ 0.4 12.13+7.5 - 1.13+2.850.125X 8.8 9.4X 3.2+6 X 0.32 9.6X 3.6+7.2X 0.2.46. 计算下面各题,能简算得要简算.96- (100X 0.48) 3.6- (1.2+0.5) X 6(967— 31) + ( 17+48) 72 X 10.1+27X 10.1.47. 用自己喜欢的方法计算.3.4X 7.8-3.9 48. 用简便方法计算6.3+0.84+3.7+8.16 100- (2.72+10.8) -0.2 50. 脱式计算0.25X 3.25X 4 6.72+3.2-2.5 21.36- 0.4— 23.4 0.8X 4.5+1.2X 4.5.54 - (6.86+3.94)0.486+0.01+3.99 17.5X 2.3- 7.5X2.3 1.25X 11 X 4 X 0.84.8X 39+61 X 4.8 45.55 - (6.82+15.55) 3.2X 99+3.22.5X 56+4.5X 56 (31.6— 11.7) -2.5-43.6X 0.9+3.6X 0.149. 计算下列各题. (能简算的要简算) 7.5-2.4-0.8X 2.5 12.5X 17+83X 12.5 399X 2.5 25- (2.5- 0.4) 3.25X67+5.75X 67+67 230- 2.5X 7.5小数除法脱式运算+简算260道参考答案与试题解析一.计算题(共50 小题)1.【解答】解:(1) 32X 12.5X 0.25=4X 8X 12.5X 0.25=(4X 0.25) X (8X 12.5) =1X 100=100(2) 6.1X 4.2+5.8X6.1=6.1X (4.2+5.8) =6.1 X 10=61(3) 1.7 士2.5 士0.4=1.7+ (2.5X 0.4) =1.7 士1=1.7 (4) 16.1 - 4.2 — 5.8=16.1- (4.2+5.8) =16.1- 10=6.1 2.【解答】解:(1) (0.6X 0.8+0.12) - 1.2=0.6 士1.2=0.5 答:商是0.5. (2) (14.81+5.19) X ( 14.81 - 5.19) =20X 9.62=192.4 答:积是192.4. (3) [ (2.7+4.5) 士12] X 0.3=[7.2士12] X 0.3=0.6X 0.3=0.18答:积是0.18. 3.【解答】解:①4.8士(1.2士0.5) =4.8士2.4=2②12.8- 12.8-5=12.8-2.56=10.24®71.4- (7X 6) =71.4士7士6=10.2士6=1.7 4.【解答】角车:①0.65 X 101 - 0.65 =0.65X ( 101 - 1) =0.65X 100=65® 12.6-3.25+6.75=12.6+ (6.75 —3.25) =12.6+3.5=16.1③6.35士0.2士0.5=6.35士(0.2X 0.5) =6.35士0.1=63.曜5.7X 1.2- 19 =5.7士19X 1.2=0.3X 1.2=0.36® 1.25X3.63X 0.8=( 1.25X 0.8) X 3.63=1 X 3.63=3.63 5.【解答】解:① 0.11X 1.8+8.2 X 0.11=0.11X ( 1.8+8.2) =0.11 X 10=1.1 ②3.5 - 3.5X 0.98=3.5X ( 1- 0.98) =3.5 X 0.02=0.07®0.75X 18士0.15=0.75士0.15X 18=5X 18=90®0.25X4.78X 8=0.25X 8X4.78=2X4.78=9.56 6.【解答】解:① 17.3士0.125-8 =17.3士(0.125X8)=17.3士1=17.3 ② 14.72X 0.7+5.28X 0.7= (14.72+5.28) X 0.7=20X 0.7=14③ 3.5 士0.56 = ( 3.5 士0.7)士( 0.56 士0.7 ) =5 士8=0.625④ 8.5 X 9.9+0.82=8.5 X ( 10 - 0.1 ) +0.82=8.5 X 10 - 8.5 X 0.1+0.82=85 - 0.85+0.82=85-(0.85 - 0.82) =85- 0.03=84.97 7.【解答】解:(1) 38.75-(24.5+8.75) =38.75- 24.5 - 8.75=38.75- 8.75 - 24.5=30 - 24.5=5.5; (2) 0.4 X 2.32 X 0.25=0.4X 0.25X 2.32=0.1 X 2.32=0.232; (3) 0.75X 101=0.75X (100+1) =0.75 X 100+0.75 X 1=75+0.75=75.75; (4) 4.2 - 3.2 X 0.9=4.2- 2.88=1.32; (5) 7.56X 99+7.56=7.56X (99+1) =7.56X 100=756; (6) 70.3- 17.48士7.6=70.3-2.3=68;(7) 3.64士5.2X 23.3=0.7X 23.3=16.31; (8) 21.8士0.8 - 1.2X 5=27.25— 6=21.25; (9) 45- (5.25-0.25) =45+ 21毛;(10) 16.5X 101 - 16.5=16.5X (101 - 1) =16.5X 100=1650;(11) 0.96- 0.3X 14=3.2X 14=44.8; (12) 1.25X 4 X 2.5X 8= (1.25X 8) X ( 4 X 2.5) =10X 10=100; ( 13) 36.45- ( 0.82+3.4X 0.2) =36.45 士(0.82+0.68) =36.45士 1.5=24.3; (14) 9.07-2.64士0.4=9.07—6.6=2.47; (15) 1.5 X 101=1.5 X ( 100+1 ) =1.5 X 100+1.5 X 1=150+1.5=151.5; ( 16) 12.6 X 7.5+8.3=94.5+8.3=102.8; (17) 13.6X 0.85 - 3.6X 0.85= (13.6 - 3.6) X 0.85=10X 0.85=8.5; (18) 104X 8.5= (100+4) X8.5=100X 8.5+4 X 8.5=850+34=884;(19) 86.4 士 6.4 - 0.4=13.5 - 0.4=13.1; ( 20) 0.25X 6.2 X 0.4=0.25 X 0.4 X 6.2=0.1 X 6.2=0.62; (21) 23X 6.5+17X 6.5= (23+17) X 6.5=40X 6.5=260; (22) 36士0.4 X 0.25=90X 0.25=22.5; (23) (24.6- 18.1) X 3.4=6.5X 3.4=22.1; (24) 7.6X 9.9+7.6 X 0.1=7.6X (9.9+0.1) =7.6X 10=76; (25) 13.6X 0.8X 12.5=13.6X (0.8X 12.5) =13.6X 10=136; (26) 23.9X 8.5 - 3.9X 8.5= (23.9 - 3.9) X 8.5=20X 8.5=170; (27) (2.55+9.6士16) 士0.42= (2.55+0.6) 士0.42=3.15士0.42=7.5; (28) 9.2士0.25士4=9.2士(0.25X4) =9.2- 1=9.2.8.【解答】解:(1) 0.75X4X 0.25X 4= (0.75X 4) X (0.25X 4) =3X 1=3 (2) 9.6+9.9X 99=9.6+9.9X (100 - 1) =9.6+9.9X 100 -9.9=9.6+990- 9.9=989.7 (3) 15.58士8.2- 0.72=1.9— 0.72=1.18 (4) 4.536士0.8 士14=5.67士14=0.405 (5) 2.8X 3.6+1.4X2.8=2.8X ( 3.6+1.4) =2.8X 5=14 (6) 6.3X10.1=6.3X (10+0.1) =6.3X 10+6.3x 0.1=63+0.63=63.63 9.【解答】解:(1) 4.2X 7.8+2.2X 4.2 =4.2X (7.8+2.2 ) =4.2X 10=42 (2) 9.5X 101=9.5X ( 100+1) =9.5X100+9.5=950+9.5=959.5 (3) (8X 3.82) X 1.25 = (8X 1.25) X3.82=10X 3.82=38.2 (4) 0.125X 72=0.125X 8 X 9=1 X 9=9 ( 5) 0.6X 3.9X 0.8 =2.34X 0.8=1.872( 6) 42 X 0.39+4.2X 6.1=42X 0.39+42 X 0.61=42X (0.39+0.61) =42X 1=42 10.【解答】解:(1)0.25 X 1.25X 16=0.25X 1.25X (2X 8) = (0.25X 2) X (1.25 X 8) =0.5X 10=5(2) 18.9- 18.9士1.4=18.9— 13.5=5.4 (3) 8.37X 1.2 - 8.37X 0.2=8.37X (1.2 - 0.2) =8.37X 1=8.37(4) 43 X 11.8+5.7 X 118=43X 11.8+57X 11.8= (43+57) X 11.8=100 X 11.8=1180 11 .【解答】解:(1 ) 6.2+5.18+2.8=6.2+2.8+5.18 =9+5.18=14.18 (2) 15.35 - (5.35+7.2) =15.35— 5.35 - 7.2=10-7.2=2.8(3) 3.63 - 1.25+17.37-8.75=(3.63+17.37) - (1.25+8.75) =21 - 10=11(4) 51.72 - 8.66 - 1.34=51.72- (8.66+1.34) =51.72 - 10=41.72 12 .【解答】解:(1) 0.7X 101 - 0.7 =0.7X (101 - 1) =0.7X 100=70(2) 0.125X 4.7X 8=0.125X 8X 4.7=1 X 4.7=4.7(3) 12.9 - 1.68- 2.32 =12.9- (1.68+2.32)=12.9- 4=8.9 (4) 567士20-5=567- (20X 5) =567士100=5.67 13.【解答】解:① 20.16 士7.2+9.8 =2.8+9.8=12.6 ; ② 6.2 X 2.7+6.5 X 7.3=16.74+47.45=64.19 ; ③ 32.8+9.6+7.2=9.6+ ( 32.8+7.2 )=9.6+40=49.6. 14.【解答】解:(1) 15.89- (5.89+6.98) =15.89- 5.89- 6.98=10-6.98=3.02; (2) 0.25X 13.7X 0.4=0.25X 0.4X 13.7=0.1X 13.7=1.37; (3) 32.7X 28+7.3X 28 = (32.7+7.3) X 28=40X 28=1120; (4) 15X 9.4 - 42=141 - 42=99; (5) 4.9+12.87- 5.38=17.77- 5.38=12.39; (6) 0.05 X 0.7 X 20X 1.7=0.05X 20X 0.7X 1.7=1 X 0.7X 1.7=0.7X 1.7=1.19.15.【解答】解:(1) 5.04X 28= (5+0.04) X28=5 X 28+0.04 X 28=1401.12=141.12; (2) (15.4 - 7.8) X 3.5 =7.6 X 3.5=26.6; (3) 3.2X4.6+3.2X 5.4=3.2X (4.6+5.4) =3.2X 10=32; (4) 0.25X 17.4X 4=0.25X 4X 17.4=1 X 17.4=17.4; (5) 20- 6.72- 3.28=20- ( 6.72+3.28) =20- 10=10; (6) 8.33+7.45+1.67+2.55=8.33^1.67+7.45+2.55=(8.33+1.67) +(7.45+2.55) =10+10=20. 16.【解答】解:(1) 0.2X 0.6X 0.5X4 = (0.2X 0.5) X (0.6X4)=0.1 X 2.4=0.24; (2) (7.5 - 2.3X 0.4) 士0.01 = 7.5 - 0.92) 士0.01=6.58士0.01=658; (3) 1.2 X 0.25+2.8 X 0.25 = ( 1.2+2.8) X 0.25=4 X 0.25=1;(4) 178.8- ( 26.4— 5.6) =178.8士20.8^^ . 17.【解答】解:(1) 3.6 -521.28+3.09=2.32+3.09=5.41(2) 3.82+2.9+0.18+9.1 =(3.82+0.18) +(9.1+2.9) =4+12=16 (3) 9.43- (6.28- 1.57) =9.43+1.57- 6.28=11 - 6.28=4.72(4) 21.32- (6.32+8.3) =21.32-6.32 - 8.3=15-8.3=6.7 (5) 13.75- (3.75+6.48) =13.75- 3.75- 6.48=10 -6.48=3.52(6) 15- 7.35-2.65=15- (7.35+2.65) =15- 10=5 18.【解答】解:① 19.81 - 2.68 - 8.32=19.81 -(2.68+8.32) =19.81 - 11=8.81 ②5.6+6.6 - 5.6+6.6= (5.6-5.6) + (6.6+6.6)=0+13.2=13.2®0.81 X 27+0.19X27=27X (0.81+0.19) =27X 1=27® 101 X 0.19-0.19=(101- 1) X 0.19=100X 0.19=19 19.【解答】解:(1 ) 9.08 - 1.76 - 4.24 =9.08 - ( 1.76+4.24 ) =9.08 - 6=3.08 ;(2) 18.38- (5.38+1.8) - 8.2=18.38- 7.18- 8.2=11.2- 8.2=3; (3) 17.45— (8.76 -6.55) =17.45- 8.76+6.55=17.45+6.55 - 8.76=24- 8.76=15.24; (4) 12.87+3.98- 3.87=12.87- 3.87+3.98=9+3.98=12.98. 20.【解答】解:① 10.8- (3.94+6.86) X0.8 =10.8士 10.8X 0.8=1 X 0.8=0.8②0.65X 201 =0.65X (200+1) =0.65 X 200+0.65 X 1=130+0.65=130.65® 12.5X 3.9X 0.8=12.5X 0.8X 3.9=10X 3.9=39® 39.8 X 0.25X 4 =39.8X ( 0.25X 4) =39.8X 1=39.8⑤37.6X 8+37.6X 2 =37.6X (8+2) =37.6 X 10=376 ⑥ 0.78X 99+0.78=0.78X ( 99+1 ) =0.78 X 100=7821.【解答】 解:(1) 21.8-7.22- 2.78=21.8- (7.22+2.78) =21.8- 10=11.8 (2) 9 - 0.24士 1.6X1.1=9- 0.15X 1.1=9- 0.165=8.835 (3) 9.12+9.12X 9 - 6.02=9.12 X ( 1+9) - 6.02=9.12X 10 - 6.02=91.2 - 6.02=85.18 ( 4 ) 45.2 X 66.7+66.7 X 53.8+66.7= (45.2+53.8+1) X 66.7=100X 66.7=6670 (5) 0.25X 0.8X 0.125X 0.4=(0.25X 0.4) X (0.125X 0.8) =0.1 X 0.1=0.01(6) 12.75士 [ 14.6- (1.3+8.2) ] =12.75 士 [14.6 - 9.5] =12.75-5.1=2.5 (7) 0.125X 36X (4士0.5) 士36=0.125X (4士0.5) X (36士36) =0.125X 8X 1=1 (8) [ (6.1 — 4.6) X 0.8 — 1] X 0.36=[1.5X 0.8 - 1] X 0.36=[ 1.2 - 1] X 0.36=0.2 X 0.36=0.072 (9) 15.6 - (4.1+0.2+6.86- 0.7) =15.6 -(4.1+0.2+9.8) =15.5— (4.1+10) =15.5- 14.1=1.4 (10) [5- (1 - 1.2X 0.8)] 士 4=[5 - ( 1 - 0.96) ] 士 4=[5 - 0.04] 士 4=4.96 士 4=1.24(11) 1 士 0.25+0.4 X 0.6=4+0.24=4.24 (12) 13.6X 3-40.6士 2=40.8— 20.3=20.5 (13) 25.8+10.5士 ( 5 -3.5) =25.8+10.5士 1.5=25.8+7=32.8 (14) 1.42- 0.36士6X 0.6=1.42— 0.36=1.07(15 ) 49.5 X 0.2 - 2.07 士 23=9.9 - 0.09=9.81 ( 16 ) 6.7+3.3 士4.4+5.6=6.7+0.75+5.6=7.45+5.6=13.05 22.【解答】 解:① 50 X (0.8+0.4) =50X 0.8+50 X 0.4=40+20=60®7.34 X 2.1+7.34X 6.8+7.34X 1.1=7.34X ( 2.1+6.8+1.1) =7.34 X 10=73.4 ③ 20.5 士 1.25 士 0.8=20.5 士 ( 1.25 X 0.8 ) =20.5 士 1=20.5 ④9.88X 9+9.88=9.88X ( 9+1) =9.88X 10=98.8 23.【解答】 解:(1) 12.6士 (1.02+3.18) =12.6士 4.2=3; (2) 5.7X 6.9+4.3X 6.9= (5.7+4.3) X 6.9=10X 6.9=69;(3) (0.81+2.7) -0.9=3.51- 0.9=3.9; (4) [ (8.4— 7.9) - 0.25] X 1.2=[0.5- 0.25] X1.2=2X1.2=24 24.【解答】 解:(1) 25 X 1.25X 32 =25X 1.25X 8X 4= (25X 4) X (1.25X8) =100X 10=1000 (2)(=金)x 35^ X 35毫 X 35=10+7=1725.【解答】解:(1) 1.6X3.9X 1.25=0.8X2X3.9X 1.25= (0.8X 1.25)X (2X 3.9) =1X 7.8=7.8(2) 4.87X2.34+48.7X 0.266=4.87X2.34+4.87X2.66=4.87 X(2.34+2.66) =4.87X 5=24.35 (3) 0.49 X 9.9 =0.49X ( 10- 0.1) =0.49X 10- 0.49X 0.1=4.9- 0.049=4.851 (4) 0.05X 0.7X 20X 1.7= (0.05X 20) X (0.7X 1.7) =1X 1.19=1.19 (5)2.5X3.2X 12.5 =2.5X0.4X 8X 12.5 = (2.5X0.4) X (8X12.5) =1X 100=100(6) 3.95X7.6+3.95X 3.4- 3.95=3.95X (7.6+3.4- 1) =3.95X 10=39.5 26.【解答】 解:(1)7.8X6.9+2.2X6.9= (7.8+2.2) X6.9=10X6.9=69 (2) 2.36 X 2.5X 4=2.36X (2.5X 4) =2.36X 10=23.6 (3) 102X 0.45= (100+2) X 0.45=100 X 0.45+2X 0.45=45+0.9=45.9 (4) 4.19X 99+4.19=4.19X (99+1) =4.19X 100=419 (5)21.36士0.8 - 12.9=26.7- 12.9=13.8(6)3.2士0.8X 0.26=4X 0.26=1.04 27.【解 答】解:(1) 6.33X 101 - 6.33=6.33X (101 - 1) =6.33X 100=633; (2) 1.6X 55.4 -55.4 X 0.6= ( 1.6 - 0.6 ) X 55.4=1 X 55.4=55.4; ( 3 ) 17.68 士5.2+2.7 X 1.5=3.4+4.05=7.45; (4) (1.1- 0.78) X (2.7- 1.95) =0.32X0.75=0.24; (5) 35.6 -5 X1.73=35.6 - 8.65=26.95; ( 6) 15 士 0.2 士2.5=15士(0.2 X 2.5) =15 士0.5=30. 28.【解答】 解:(1) 2.5X 1.37X 0.4=2.5X 0.4X 1.37=1 X 1.37=1.37;79(3) 78 X(79— 1) X —=79X(2) 4.8X 0.25X 25= (4X 4X 0.3) X 0.25X 25= (4X 0.25) X ( 4X 25) X 0.3=1 X 100X0.3=30; (3) 0.89X 4.8+0.89X 5.2=0.89X (4.8+5.2) =0.89X 10=8.9; (4) 101X 0.78X 20=101 X (0.78X 20) =101 X 15.6= (100+1) X 15.6=100X 15.6+1 X 15.6=1560+15.6=1575.6; (5) 8.8X 1.25X 15= (8 X 1.1) X 1.25X 15=(8 X 1.25) X (1.1 X 15) =10 X 16.5=165; ( 6 ) 4.3 X 0.8 X 5=4.3 X ( 0.8 X 5) =4.3 X 4=17.2. 29.【解答】解:(1) 44.28-0.9-4.1=49.2+4.1=12;(2) 0.25X 0.39X 4= (0.25X 4) X 0.39=1 X 0.39=0.39; (3) 7.6+7.6 X 99=7.6X ( 1+99) =7.6X 100=760; (4) 9.07-22.78士3.4=9.07- 6.7=2.37; (5) 4.8X 99+4.8=4.8X (99+1) =4.8 X 100=480 ; ( 6 ) 6.3 X 10.1=6.3 X ( 10+0.1 ) =6.3 X 10+6.3 X 0.1=63+0.63=63.63. 30.【解答】解:(1) 5.8+3.8X 0.25=5.8+0.95=6.75 (2) 1.7X (4.65-3.87) =1.7X 0.78=1.326 (3) 1.25X 4.3X 0.8=1.25X 0.8X 4.3=1 X 4.3=4.3(4) 4.5X 102=4.5X ( 100+2) =4.5X 100+4.5X 2=450+9=459 (5) 0.54X 101 - 0.54=0.54X (101- 1) =0.54X 100=54(6) 3.4X 2.5+6.6X 2.5= (3.4+6.6) X 2.5=10 X 2.5=25 31.【解答】解:① 0.45X 12 X 0.2=0.45X 0.2X 12=0.09X 12=1.08 ② 6.2X2.1 - 2.1 =2.1 X (6.2- 1) =2.1 X 5.2=10.92 ③0.9X 0.8X 100=0.72X 100=72 ④ 2.8 - 2.8 X 0.15 =2.8 X ( 1 - 0.15) =2.8 X 0.85=2.38 ⑤ 2.8 X 1.43+0.57 =4.004+0.57=4.574 ⑥72 X 0.81+10.3=58.32+10.3=68.62 ⑦10 -6.06+8.5=3.94+8.5=12.44 ⑧ 6 X 0.25 X 1.8 =1.5 X 1.8=2.7⑨7.06 X 2.4 - 5.8=16.944-5.8=11.144 32.【解答】解:(1) 0.25X 9.87X 4 =0.25X 4X 9.87=1X 9.87=9.87; (2) 36.2X 1.8+13.8X 1.8 = (36.2+13.8) X 1.8=50X 1.8=90; (3)0.125X 2.3X 8=0.125X 8 X2.3=1 X 2.3=2.3; (4) 0.73X 102 =0.73X (100+2) =0.73 X 100+0.73X 2=73+1.46=74.46; (5) (6.8+2.6) X 5 =6.8X 5+2.6X5=34+13=47; (6) 0.23 X 98=0.23X ( 100 — 2) =0.23X 100 -0.23X2=23-0.46=22.54. 33.【解答】解:(1) 12.5X 32X 2.5 =12.5X 4X 8X 2.5=(12.5X 8) X (2.5X 4) =100X 10=1000;(2) 6.8X 9.9 =6.8X (10-0.1)=6.8X 10- 6.8X 0.1=68— 0.68=67.32; (3) 7.2士[1.8X (3.4— 2.9) ] =7.2-[1.8X 0.5] =7.2- 0.9=8. 34.【解答】解:(1) 3.4X 9+3.4=30.6+3.4=34; (2) 6.4士0.8- 1.5X4=8- 6=2; (3) 3.78士0.25士4=3.78士(0.25X4) =3.78士1=3.78;(4) 17- [ (1.2+0.5) X5]=17士[1.7X 5] =17士8.5=2. 35.【解答】解:(1)2.5X 1.25X 8X 0.4 = (2.5X 0.4) X (1.25X 8) =1X 10=10; (2) 12.8X 1.7+87.2X 1.7 =( 12.8+87.2) X 1.7=100X 1.7=170; ( 3) 100 - 4.35 - 5.65=100-(4.35+5.65) =100- 10=90. 36.【解答】解:(1) 4+7.6X 15 =4+114=118; (2)26.08士0.25士4=26.08士(0.25X 4) =26.08士1=26.08; (3) 19.7+ (80.5士35X 0.2) =19.7+(2.3X 0.2) =19.7+0.46=20.16. 37.【解答】解:(1) 1.25X 2.25X 0.8=1.25X 0.8X 2.25=1 X 2.25=2.25; (2) 9.7X 99+9.7=9.7X (99+1) =9.7X 100=970; (3) 4.8X 7.8+78X 0.52=4.8X 7.8+7.8X 5.2= (4.8+5.2) X 7.8=10X 7.8=78; (4) 3.65X 10.1=3.65X (10+0.1) =3.65X 10+3.65X 0.1=36.5+0.365=36.865. 38.【解答】解:① 12.36-6.49 - 3.51=12.36- (6.49+3.51) =12.36- 10=2.36;②8.5X 3.8+8.5 X 6.2=8.5X (3.8+6.2) =8.5X 10=85;③ 17.3X 0.25X 8=17.3X ( 0.25X 8) =17.3 X 2=34.6;④ 15.32 - 1.8X 5 - 3.46=15.32- 9 -3.46=6.32- 3.46=2.86;⑤199X 2.6= (200— 1) X 2.6=200X 2.6 - 1 X2.6=520— 2.6=517.4;⑥3.6士[ (1.3+0.6) X 5] =3.6 -[1.9X 5]=3.6 士9.5理.39.【解答】解:(1) 8.5+6.85 - 6.35 =8.5+ (6.85- 6.35) =8.5+0.5=9; (2) 3.9+0.1 - 3.9+0.1 = (3.9-3.9) + (0.1+0.1) =0+0.2=0.2;(3) 12.6 - (3.75+5.08) =12.6— 8.83=3.77. 40.【解答】解:(1) 6.09 - 9.13士8.3=6.09— 1.1=4.99 (2) 3.84X 9.6+0.96X 61.6 = (3.84+6.16) X9.6=10X 9.6=96(3) 4.86X 99=4.86X (100- 1) =4.86X 100- 4.86=486- 4.86=481.14 (4) 5.68 X 4+4.32 士0.25 =5.68X 4+4.32X 4= (5.68+4.32) X4=10X 4=40 (5) 6.4X 4.5+3.6 X 4.5= ( 6.4+3.6 ) X 4.5=10 X 4.5=45 41 .【解答】解:① 10.5+61 X18=10.5+1098=1108.5 ②(3.14+12.6) 士8=15.74士8=1.9675^4.5士(15士3) =4.5士5=0.9®75+448士4X 19=75+112X 19=75+2128=2203 42.【解答】角牟:(1) (18.5X 3.8+3.8X 2.5) 士0.19 =3.8X (18.5+2.5) 士0.19 =3.8X 21 士0.19=3.8士0.19 X 21=200X 21=4200 (2) [32 - ( 7.25+0.75 X 8) ] 士50=[ 32 - (7.25+6) ] - 50=[32- 13.25] -50=18.75士50=0.375 43.【解答】解:① 25.32 -(3.4 - 1.2) =25.32-2.2=23.12® 12 - 0.62-4.38=12- (0.62+4.38) =12- 5=7 44.【解答】解:(1)5.12+2.54+4.88=5.12+4.88+2.54=10+2.54=12.54; (2) 12.5 X 17.8 X 0.8=12.5X 0.8 X 17.8=10 X 17.8=178; ( 3) 0.24 X 0.48 X 4=0.1152X 4=0.4608; (4) 9.9X2.5= (10- 0.1) X 2.5=10X2.5- 0.1 X2.5=25- 0.25=24.75;(5) 9.4X 5.8+10.6X 5.8= (9.4+10.6) X 5.8=20X 5.8=116; (6) 0.66X 101=0.66 X (100+1) =0.66X 100+0.66X 1=66+0.66=66.66; (7)4.8X 0.25= 1.2X 4) X 0.25=1.2 X (4 X 0.25) =1.2X 1=1.2; (8) 2.33X 0.5X 4 =2.33X (0.5X4) =2.33X 2=4.66;(9) 1.3 X 2.5+0.7X 2.5=( 1.3+0.7) X 2.5=2X 2.5=5 ; (10) 1.26X 0.6+1.26 X 0.4=1.26 X (0.6+0.4) =1.26X 1=1.26; (11) 102X 0.55= (100+2) X0.55=100X 0.55+2 X 0.55=55+1.1=56.1 ; ( 12 ) 0.034 X 0.5 X 0.2=0.034 X ( 0.5 X 0.2 ) =0.034 X 0.1=0.0034.45.【解答】解:(1) 13.38+0.98=13.38+( 1 - 0.02) =13.38+1 -0.02=14.38- 0.02=14.36; (2) 7.02- 2.98 =7.02- ( 3- 0.02) =7.02- 3+0.02 =4.02+0.02=4.04;(3) 6.57- (0.68 -0.39+0.32) =6.57- (0.68+0.32- 0.39) =6.57 -(1 - 0.39) =6.57— 0.61=5.96;(4) 13.8士(1.38X 0.2) =13.8士 1.38士0.2=10 士0.2=50; (5) 30.7 - 0.12X 2 -0.76=30.7— 0.24- 0.76=30.7— (0.24+0.76)=30.7- 1=29.7; (6) 7.8 X 1.01=7.8X (1+0.01) =7.8X 1+7.8 X 0.01=7.8+0.078=7.878;(7) 18.4-6.5+1.6+3.5 =(18.4+1.6) — (6.5— 3.5) =20— 3=17; (8)7.8士0.6+7.8士0.4=13+19.5=32.5; (9) 12.13+7.5 - 1.13+2.85= ( 12.13 - 1.13) + (7.5+2.85) =11 - 10.35=0.65; (10) 0.125X 8.8=0.125X (8+0.8) =0.125X 8+0.125 X 0.8=1+0.1=1.1; ( 11) 9.4 X 3.2+6 X 0.32 =9.4 X 3.2+0.6 X 3.2=(9.4+0.6) X 3.2=10X 3.2=32; (12) 9.6 X 3.6+7.2 X 0.2=9.6X 3.6+3.6X 2X 0.2=9.6X 3.6+3.6X 0.4= (9.6+0.4) X 3.6=10X 3.6=36. 46.【解答】解:(1) 96 士(100X 0.48) =96士48=2; (2) 3.6士(1.2+0.5) X 6=3.6士1.7 X 6辛X 6^^; (3) (967-31) 士( 17+48) =936+ 65=14.4; (4) 72X 10.1+27X 10.1 =(72+27 ) X 10.1=99 X 10.1=99 X ( 10+0.1 ) =99 X 10+99 X0.1=990+9.9=999.9. 47.【解答】解:(1) 3.4X 7.8- 3.9=26.52士3.9=6.8; (2)54- (3.94+6.86) =54- 10.8=5. 48.【解答】解:① 0.486+0.01+3.99 =0.486+(0.01+3.99) =0.486+4=4.486 ② 17.5X 2.3- 7.5X 2.3 =2.3X ( 17.5-7.5) =2.3 X 10=23 ③1.25X 11X 4X 0.8=(1.25X 0.8) X (11X 4) =1X 44=44®4.8X 39+61X 4.8=4.8X ( 39+61) =4.8 X 100=480 ⑤45.55 - ( 6.82+15.55) =45.55 - 6.82 一15.55=45.55- 15.55- 6.82=30- 6.82=23.18⑥3.2 X 99+3.2=3.2X ( 99+1) =3.2X 100=32C@2.5 X 56+4.5 X 56 =56 X (2.5+4.5) =56X 7=392® (31.6 - 11.7)- 2.5-4 =19.9+ (2.5X4) =19.9+ 10=1.99®3.6X 0.9+3.6X 0.1=3.6X (0.9+0.1) =3.6X 1=3.6 49.【解答】解:(1) 7.5- 2.4-0.8X2.5 =7.5— 3X 2.5=7.5— 7.5=0;(2) 12.5X 17+83X 12.5=12.5X ( 17+83) =12.5X 100=1250; (3) 399X 2.5 = (400- 1) X 2.5=400X2.5 - 2.5=1000-2.5=997.25; (4) 25- ( 2.5- 0.4) =25 -2.5X 0.4=10X 0.4=4; (5) 3.25X 67+5.75X 67+67 = (3.25+5.75+1) X 67=10 X 67=670; (6) 230+ 2.5X 7.5=92X 7.5=690; (7) 6.3+0.84+3.7+8.16= (6.3+3.7) + (0.84+8.16) =10+9=19; (8) 100- ( 2.72+10.8) -0.2=100- 13.52-0.2=100 -67.6=32.4. 50.【解答】解:(1) 0.25X 3.25X 4=0.25X 4X 3.25=1 X 3.25=3.25(2) 6.72+3.2- 2.5=6.72+1.28=8 (3) 21.36-0.4 - 23.4=53.4-23.4=30 (4) 0.8 X 4.5+1.2X 4.5= (0.8+1.2) X4.5=2X 4.5=9。

(完整)小数除法脱式运算+简算260道含答案(2),推荐文档

(完整)小数除法脱式运算+简算260道含答案(2),推荐文档

小数除法脱式运算+简算260道一.计算题(共50小题)1.用你喜欢的方法计算.32×12.5×0.25 6.1×4.2+5.8×6.1 1.7÷2.5÷0.416.1﹣4.2﹣5.8.3.脱式计算4.8÷(1.2÷0.5)12.8﹣12.8÷571.4÷(7×6)4.用你喜欢的方法计算0.65×101﹣0.65 12.6﹣3.25+6.756.35÷0.2÷0.5 5.7×1.2÷19 1.25×3.63×0.8.5.我能用喜欢的方法计算下面各题.0.11×1.8+8.2×0.11 3.5﹣3.5×0.980.75×18÷0.150.25×4.78×8.6.能简算的要简算.17.3÷0.125÷8 14.72×0.7+5.28×0.73.5÷0.56 8.5×9.9+0.82.7.递等式计算,有简便运算的用简便方法38.75﹣(24.5+8.75)0.4×2.32×0.250.75×101 4.2﹣3.2×0.97.56×99+7.5670.3﹣17.48÷7.6 3.64÷5.2×23.321.8÷0.8﹣1.2×5 45÷(5.25÷0.25)16.5×101﹣16.50.96÷0.3×14 1.25×4×2.5×836.45÷(0.82+3.4×0.2)9.07﹣2.64÷0.4 1.5×10112.6×7.5+8.3 13.6×0.85﹣3.6×0.85104×8.586.4÷6.4﹣0.40.25×6.2×0.423×6.5+17×6.536÷0.4×0.25(24.6﹣18.1)×3.47.6×9.9+7.6×0.1 13.6×0.8×12.523.9×8.5﹣3.9×8.5(2.55+9.6÷16)÷0.429.2÷0.25÷48.脱式计算(能简算的要简算)0.75×4×0.25×49.6+9.9×9915.58÷8.2﹣0.724.536÷0.8÷14 2.8×3.6+1.4×2.8 6.3×10.1.9.脱式计算(能简算的要用简算)4.2×7.8+2.2×4.2 9.5×101(8×3.82)×1.250.125×720.6×3.9×0.8 42×0.39+4.2×6.110.脱式计算,能简算的要简算0.25×1.25×1618.9﹣18.9÷1.48.37×1.2﹣8.37×0.243×11.8+5.7×118.11.用简便方法计算.6.2+5.18+2.8 15.35﹣(5.35+7.2)3.63﹣1.25+17.37﹣8.75 51.72﹣8.66﹣1.34.12.脱式计算,能简算的要简算.0.7×101﹣0.7 0.125×4.95×8 12.9﹣1.68﹣2.32 567÷20÷5.13.用递等式计算,能简算的要简算.20.16÷7.2+9.8 6.2×2.7+6.5×7.3 32.8+9.6+7.2.14.脱式计算:能简算的要简算15.89﹣(5.89+6.98)0.25×13.7×0.432.7×28+7.3×2815×9.4﹣42 4.9+12.87﹣5.380.05×0.7×20×1.7.15.计算下面各题,能简算的要简算.5.04×28(15.4﹣7.8)×3.5 3.2×4.6+3.2×5.40.25×17.4×4 20﹣6.72﹣3.28 8.33+7.45+1.67+2.5516.脱式计算.0.2×0.6×0.5×4 (7.5﹣2.3×0.4)÷0.011.2×0.25+2.8×0.25 178.8÷(26.4﹣5.6)17.能简算的要简算3.6﹣1.28+3.09 3.82+2.9+0.18+9.1 9.43﹣(6.28﹣1.57)21.32﹣(6.32+8.3)13.75﹣(3.75+6.48)15﹣7.35﹣2.6518.混合运算,能简便就简便19.81﹣2.68﹣8.32 5.6+6.6﹣5.6+6.60.81×27+0.19×27101×0.19﹣0.19.19.用简便方法计算9.08﹣1.76﹣4.24 18.38﹣(5.38+1.8)﹣8.217.45﹣(8.76﹣6.55)12.87+3.98﹣3.87.20.脱式计算,能简便的用简便方法计算.10.8÷(3.94+6.86)×0.80.65×201 12.5×3.9×0.839.8×0.25×4 37.6×8+37.6×20.78×99+0.78.21.脱式计算:21.8﹣7.22﹣2.789﹣0.24÷1.6×1.19.12+9.12×9﹣6.0245.2×66.7+66.7×53.8+66.70.25×0.8×0.125×0.412.75÷[14.6﹣(1.3+8.2)] 0.125×36×(4÷0.5)÷36[(6.1﹣4.6)×0.8﹣1]×0.3615.6﹣(4.1+0.2+6.86÷0.7)[5﹣(1﹣1.2×0.8)]÷41÷0.25+0.4×0.613.6×3﹣40.6÷225.8+10.5÷(5﹣3.5) 1.42﹣0.36÷6×0.649.5×0.2﹣2.07÷236.7+3.3÷4.4+5.622.计算下面各题(能简算的要简算)50×(0.8+0.4)7.34×2.1+7.34×6.8+7.34×1.120.5÷1.25÷0.8 9.88×9+9.88.23.计算下列各题(能用简便算法的要用简便算法).12.6÷(1.02+3.18) 5.7×6.9+4.3×6.9(0.81+2.7)÷0.9[(8.4﹣7.9)÷0.25]×1.2.25.能简算的用简便方法计算.(写出主要简便过程,无过程不得分)1.6×3.9×1.25 4.87×2.34+48.7×0.2660.49×9.9 0.05×0.7×20×1.72.5×3.2×12.5 3.95×7.6+3.95×3.4﹣3.95.26.计算下面各题,能简算的要简算7.8×6.9+2.2×6.9 2.36×2.5×4102×0.454.19×99+4.1921.36÷0.8﹣12.9 3.2÷0.8×0.2627.计算(能简算的要简算).6.33×101﹣6.33 1.6×55.4﹣55.4×0.617.68÷5.2+2.7×1.5(1.1﹣0.78)×(2.7﹣1.95)35.6﹣5×1.7315÷0.2÷2.528.脱式计算(能简算的要简算)2.5×1.37×0.4 4.8×0.25×250.89×4.8+0.89×5.2101×0.78×208.8×1.25×15 4.3×0.8×529.计算下面各题,能简算的要简算.44.28÷0.9÷4.10.25×0.39×47.6+7.6×999.07﹣22.78÷3.4 4.8×99+4.8 6.3×10.130.下面各题,能简算的就要简算.5.8+3.8×0.25 1.7×(4.65﹣3.87) 1.25×4.3×0.84.5×1020.54×101﹣0.54 3.4×2.5+6.6×2.5.31.计算下列各题.0.45×12×0.2 6.2×2.1﹣2.1 0.9×0.8×1002.8﹣2.8×0.15 2.8×1.43+0.57 72×0.81+10.310﹣6.06+8.56×0.25×1.8 7.06×2.4﹣5.832.用简便方法计算.0.25×9.87×4 36.2×1.8+13.8×1.8 0.125×2.3×80.73×102 (6.8+2.6)×5 0.23×98.33.能用简便方法的用简便方法计算12.5×32×2.5 6.8×9.9 7.2÷[1.8×(3.4﹣2.9)].34.用你喜欢的方法计算.3.4×9+3.4 6.4÷0.8﹣1.5×4 3.78÷0.25÷4 17÷[(1.2+0.5)×5].35.用你喜欢的方法计算2.5×1.25×8×0.4 12.8×1.7+87.2×1.7 100﹣4.35﹣5.65.36.用递等式计算(能简算的要简算).4+7.6×15 26.08÷0.25÷419.7+(80.5÷35×0.2)37.计算,能简算的要简算.1.25×2.25×0.8 9.7×99+9.7 4.8×7.8+78×0.523.65×10.1.38.计算下面各题.(能简算的用简便算法)①12.36﹣6.49﹣3.51②8.5×3.8+8.5×6.2③17.3×0.25×8④15.32﹣1.8×5﹣3.46⑤199×2.6⑥3.6÷[(1.3+0.6)×5] 39.计算8.5+6.85﹣6.35 3.9+0.1﹣3.9+0.1 12.6﹣(3.75+5.08)40.计算,能简算的要简算6.09﹣9.13÷8.3 3.84×9.6+0.96×61.6 4.86×995.68×4+4.32÷0.256.4×4.5+3.6×4.5.41.脱式计算.10.5+61×18 (3.14+12.6)÷8 4.5÷(15÷3)75+448÷4×19.42.计算:(18.5×3.8+3.8×2.5)÷0.19 [32﹣(7.25+0.75×8)]÷50.43.脱式计算,能简算的就简算:25.32﹣(3.4﹣1.2)12﹣0.62﹣4.38.44.用简便方法计算下面各题.5.12+2.54+4.8812.5×17.8×0.8 0.24×0.48×49.9×2.59.4×5.8+10.6×5.8 0.66×101 4.8×0.25 2.33×0.5×41.3×2.5+0.7×2.5 1.26×0.6+1.26×0.4 102×0.55 0.034×0.5×0.245.计算.(怎样简便就怎么计算)13.38+0.98=7.02﹣2.98 6.57﹣(0.68﹣0.39+0.32)13.8÷(1.38×0.2)30.7﹣0.12×2﹣0.76 7.8×1.0118.4﹣6.5+1.6+3.5 7.8÷0.6+7.8÷0.412.13+7.5﹣1.13+2.850.125×8.89.4×3.2+6×0.32 9.6×3.6+7.2×0.2.46.计算下面各题,能简算得要简算.96÷(100×0.48) 3.6÷(1.2+0.5)×6(967﹣31)÷(17+48)72×10.1+27×10.1.47.用自己喜欢的方法计算.3.4×7.8÷3.9 54÷(6.86+3.94)48.用简便方法计算0.486+0.01+3.99 17.5×2.3﹣7.5×2.3 1.25×11×4×0.8 4.8×39+61×4.8 45.55﹣(6.82+15.55) 3.2×99+3.22.5×56+4.5×56 (31.6﹣11.7)÷2.5÷43.6×0.9+3.6×0.149.计算下列各题.(能简算的要简算)7.5﹣2.4÷0.8×2.5 12.5×17+83×12.5399×2.5 25÷(2.5÷0.4)3.25×67+5.75×67+67 230÷2.5×7.5 6.3+0.84+3.7+8.16 100﹣(2.72+10.8)÷0.250.脱式计算0.25×3.25×4 6.72+3.2÷2.521.36÷0.4﹣23.40.8×4.5+1.2×4.5.小数除法脱式运算+简算260道参考答案与试题解析一.计算题(共50小题)1.【解答】解:(1)32×12.5×0.25=4×8×12.5×0.25=(4×0.25)×(8×12.5)=1×100=100(2)6.1×4.2+5.8×6.1=6.1×(4.2+5.8)=6.1×10=61(3)1.7÷2.5÷0.4=1.7÷(2.5×0.4)=1.7÷1=1.7(4)16.1﹣4.2﹣5.8=16.1﹣(4.2+5.8)=16.1﹣10=6.12.【解答】解:(1)(0.6×0.8+0.12)÷1.2=0.6÷1.2=0.5答:商是0.5.(2)(14.81+5.19)×(14.81﹣5.19)=20×9.62=192.4答:积是192.4.(3)[(2.7+4.5)÷12]×0.3=[7.2÷12]×0.3=0.6×0.3=0.18答:积是0.18.3.【解答】解:①4.8÷(1.2÷0.5)=4.8÷2.4=2②12.8﹣12.8÷5=12.8﹣2.56=10.24③71.4÷(7×6)=71.4÷7÷6=10.2÷6=1.74.【解答】解:①0.65×101﹣0.65 =0.65×(101﹣1)=0.65×100=65②12.6﹣3.25+6.75=12.6+(6.75﹣3.25)=12.6+3.5=16.1③6.35÷0.2÷0.5=6.35÷(0.2×0.5)=6.35÷0.1=63.5④5.7×1.2÷19 =5.7÷19×1.2=0.3×1.2=0.36⑤1.25×3.63×0.8=(1.25×0.8)×3.63=1×3.63=3.635.【解答】解:①0.11×1.8+8.2×0.11=0.11×(1.8+8.2)=0.11×10=1.1②3.5﹣3.5×0.98=3.5×(1﹣0.98)=3.5×0.02=0.07③0.75×18÷0.15=0.75÷0.15×18=5×18=90④0.25×4.78×8=0.25×8×4.78=2×4.78=9.566.【解答】解:①17.3÷0.125÷8 =17.3÷(0.125×8)=17.3÷1=17.3 ②14.72×0.7+5.28×0.7=(14.72+5.28)×0.7=20×0.7=14③3.5÷0.56 =(3.5÷0.7)÷(0.56÷0.7)=5÷8=0.625④8.5×9.9+0.82=8.5×(10﹣0.1)+0.82=8.5×10﹣8.5×0.1+0.82=85﹣0.85+0.82=85﹣(0.85﹣0.82)=85﹣0.03=84.977.【解答】解:(1)38.75﹣(24.5+8.75)=38.75﹣24.5﹣8.75=38.75﹣8.75﹣24.5=30﹣24.5=5.5;(2)0.4×2.32×0.25=0.4×0.25×2.32=0.1×2.32=0.232;(3)0.75×101=0.75×(100+1)=0.75×100+0.75×1=75+0.75=75.75;(4)4.2﹣3.2×0.9=4.2﹣2.88=1.32;(5)7.56×99+7.56=7.56×(99+1)=7.56×100=756;(6)70.3﹣17.48÷7.6=70.3﹣2.3=68;(7)3.64÷5.2×23.3=0.7×23.3=16.31;(8)21.8÷0.8﹣1.2×5=27.25﹣6=21.25;(9)45÷(5.25÷0.25)=45÷21=;(10)16.5×101﹣16.5=16.5×(101﹣1)=16.5×100=1650;(11)0.96÷0.3×14=3.2×14=44.8;(12)1.25×4×2.5×8=(1.25×8)×(4×2.5)=10×10=100;(13)36.45÷(0.82+3.4×0.2)=36.45÷(0.82+0.68)=36.45÷1.5=24.3;(14)9.07﹣2.64÷0.4=9.07﹣6.6=2.47;(15)1.5×101=1.5×(100+1)=1.5×100+1.5×1=150+1.5=151.5;(16)12.6×7.5+8.3=94.5+8.3=102.8;(17)13.6×0.85﹣3.6×0.85=(13.6﹣3.6)×0.85=10×0.85=8.5;(18)104×8.5=(100+4)×8.5=100×8.5+4×8.5=850+34=884;(19)86.4÷6.4﹣0.4=13.5﹣0.4=13.1;(20)0.25×6.2×0.4=0.25×0.4×6.2=0.1×6.2=0.62;(21)23×6.5+17×6.5=(23+17)×6.5=40×6.5=260;(22)36÷0.4×0.25=90×0.25=22.5;(23)(24.6﹣18.1)×3.4=6.5×3.4=22.1;(24)7.6×9.9+7.6×0.1=7.6×(9.9+0.1)=7.6×10=76;(25)13.6×0.8×12.5=13.6×(0.8×12.5)=13.6×10=136;(26)23.9×8.5﹣3.9×8.5=(23.9﹣3.9)×8.5=20×8.5=170;(27)(2.55+9.6÷16)÷0.42=(2.55+0.6)÷0.42=3.15÷0.42=7.5;(28)9.2÷0.25÷4=9.2÷(0.25×4)=9.2÷1=9.2.8.【解答】解:(1)0.75×4×0.25×4=(0.75×4)×(0.25×4)=3×1=3(2)9.6+9.9×99=9.6+9.9×(100﹣1)=9.6+9.9×100﹣9.9=9.6+990﹣9.9=989.7(3)15.58÷8.2﹣0.72=1.9﹣0.72=1.18(4)4.536÷0.8÷14=5.67÷14=0.405(5)2.8×3.6+1.4×2.8=2.8×(3.6+1.4)=2.8×5=14(6)6.3×10.1=6.3×(10+0.1)=6.3×10+6.3×0.1=63+0.63=63.639.【解答】解:(1)4.2×7.8+2.2×4.2 =4.2×(7.8+2.2 )=4.2×10=42(2)9.5×101=9.5×(100+1)=9.5×100+9.5=950+9.5=959.5(3)(8×3.82)×1.25 =(8×1.25)×3.82=10×3.82=38.2(4)0.125×72=0.125×8×9=1×9=9(5)0.6×3.9×0.8 =2.34×0.8=1.872(6)42×0.39+4.2×6.1=42×0.39+42×0.61=42×(0.39+0.61)=42×1=42 10.【解答】解:(1)0.25×1.25×16=0.25×1.25×(2×8)=(0.25×2)×(1.25×8)=0.5×10=5(2)18.9﹣18.9÷1.4=18.9﹣13.5=5.4(3)8.37×1.2﹣8.37×0.2=8.37×(1.2﹣0.2)=8.37×1=8.37(4)43×11.8+5.7×118=43×11.8+57×11.8=(43+57)×11.8=100×11.8=118011.【解答】解:(1)6.2+5.18+2.8 =6.2+2.8+5.18 =9+5.18=14.18 (2)15.35﹣(5.35+7.2)=15.35﹣5.35﹣7.2=10﹣7.2=2.8(3)3.63﹣1.25+17.37﹣8.75=(3.63+17.37)﹣(1.25+8.75)=21﹣10=11 (4)51.72﹣8.66﹣1.34=51.72﹣(8.66+1.34)=51.72﹣10=41.7212.【解答】解:(1)0.7×101﹣0.7 =0.7×(101﹣1)=0.7×100=70(2)0.125×4.7×8=0.125×8×4.7=1×4.7=4.7(3)12.9﹣1.68﹣2.32 =12.9﹣(1.68+2.32)=12.9﹣4=8.9(4)567÷20÷5=567÷(20×5)=567÷100=5.6713.【解答】解:①20.16÷7.2+9.8 =2.8+9.8=12.6;②6.2×2.7+6.5×7.3 =16.74+47.45=64.19;③32.8+9.6+7.2=9.6+(32.8+7.2)=9.6+40=49.6.14.【解答】解:(1)15.89﹣(5.89+6.98)=15.89﹣5.89﹣6.98=10﹣6.98=3.02;(2)0.25×13.7×0.4=0.25×0.4×13.7=0.1×13.7=1.37;(3)32.7×28+7.3×28 =(32.7+7.3)×28=40×28=1120;(4)15×9.4﹣42=141﹣42=99;(5)4.9+12.87﹣5.38=17.77﹣5.38=12.39;(6)0.05×0.7×20×1.7=0.05×20×0.7×1.7=1×0.7×1.7=0.7×1.7=1.19.15.【解答】解:(1)5.04×28=(5+0.04)×28=5×28+0.04×28=140+1.12=141.12;(2)(15.4﹣7.8)×3.5 =7.6×3.5 =26.6;(3)3.2×4.6+3.2×5.4=3.2×(4.6+5.4)=3.2×10=32;(4)0.25×17.4×4=0.25×4×17.4=1×17.4=17.4;(5)20﹣6.72﹣3.28=20﹣(6.72+3.28)=20﹣10=10;(6)8.33+7.45+1.67+2.55=8.33+1.67+7.45+2.55=(8.33+1.67)+(7.45+2.55)=10+10=20.16.【解答】解:(1)0.2×0.6×0.5×4 =(0.2×0.5)×(0.6×4)=0.1×2.4=0.24;(2)(7.5﹣2.3×0.4)÷0.01=(7.5﹣0.92)÷0.01=6.58÷0.01=658;(3)1.2×0.25+2.8×0.25 =(1.2+2.8)×0.25=4×0.25=1;(4)178.8÷(26.4﹣5.6)=178.8÷20.8=.17.【解答】解:(1)3.6﹣1.28+3.09=2.32+3.09=5.41(2)3.82+2.9+0.18+9.1 =(3.82+0.18)+(9.1+2.9)=4+12=16(3)9.43﹣(6.28﹣1.57)=9.43+1.57﹣6.28=11﹣6.28=4.72(4)21.32﹣(6.32+8.3)=21.32﹣6.32﹣8.3=15﹣8.3=6.7(5)13.75﹣(3.75+6.48)=13.75﹣3.75﹣6.48=10﹣6.48=3.52(6)15﹣7.35﹣2.65=15﹣(7.35+2.65)=15﹣10=518.【解答】解:①19.81﹣2.68﹣8.32=19.81﹣(2.68+8.32)=19.81﹣11=8.81②5.6+6.6﹣5.6+6.6=(5.6﹣5.6)+(6.6+6.6)=0+13.2=13.2③0.81×27+0.19×27=27×(0.81+0.19)=27×1=27④101×0.19﹣0.19=(101﹣1)×0.19=100×0.19=1919.【解答】解:(1)9.08﹣1.76﹣ 4.24 =9.08﹣(1.76+4.24)=9.08﹣6=3.08;(2)18.38﹣(5.38+1.8)﹣8.2=18.38﹣7.18﹣8.2=11.2﹣8.2=3;(3)17.45﹣(8.76﹣6.55)=17.45﹣8.76+6.55=17.45+6.55﹣8.76=24﹣8.76=15.24;(4)12.87+3.98﹣3.87=12.87﹣3.87+3.98=9+3.98=12.98.20.【解答】解:①10.8÷(3.94+6.86)×0.8=10.8÷10.8×0.8=1×0.8=0.8②0.65×201 =0.65×(200+1)=0.65×200+0.65×1=130+0.65=130.65③12.5×3.9×0.8=12.5×0.8×3.9=10×3.9=39④39.8×0.25×4 =39.8×(0.25×4)=39.8×1=39.8⑤37.6×8+37.6×2=37.6×(8+2)=37.6×10=376⑥0.78×99+0.78=0.78×(99+1)=0.78×100=78 21.【解答】解:(1)21.8﹣7.22﹣2.78=21.8﹣(7.22+2.78)=21.8﹣10=11.8(2)9﹣0.24÷1.6×1.1=9﹣0.15×1.1=9﹣0.165=8.835(3)9.12+9.12×9﹣6.02=9.12×(1+9)﹣6.02=9.12×10﹣6.02=91.2﹣6.02=85.18(4)45.2×66.7+66.7×53.8+66.7=(45.2+53.8+1)×66.7=100×66.7=6670(5)0.25×0.8×0.125×0.4=(0.25×0.4)×(0.125×0.8)=0.1×0.1=0.01(6)12.75÷[14.6﹣(1.3+8.2)]=12.75÷[14.6﹣9.5]=12.75÷5.1=2.5(7)0.125×36×(4÷0.5)÷36=0.125×(4÷0.5)×(36÷36)=0.125×8×1=1(8)[(6.1﹣4.6)×0.8﹣1]×0.36=[1.5×0.8﹣1]×0.36=[1.2﹣1]×0.36=0.2×0.36=0.072(9)15.6﹣(4.1+0.2+6.86÷0.7)=15.6﹣(4.1+0.2+9.8)=15.5﹣(4.1+10)=15.5﹣14.1=1.4(10)[5﹣(1﹣1.2×0.8)]÷4=[5﹣(1﹣0.96)]÷4=[5﹣0.04]÷4=4.96÷4=1.24(11)1÷0.25+0.4×0.6=4+0.24=4.24(12)13.6×3﹣40.6÷2=40.8﹣20.3=20.5(13)25.8+10.5÷(5﹣3.5)=25.8+10.5÷1.5=25.8+7=32.8(14)1.42﹣0.36÷6×0.6=1.42﹣0.36=1.07(15)49.5×0.2﹣ 2.07÷23=9.9﹣0.09=9.81(16) 6.7+3.3÷4.4+5.6=6.7+0.75+5.6=7.45+5.6=13.0522.【解答】解:①50×(0.8+0.4)=50×0.8+50×0.4=40+20=60②7.34×2.1+7.34×6.8+7.34×1.1=7.34×(2.1+6.8+1.1)=7.34×10=73.4③20.5÷1.25÷0.8=20.5÷(1.25×0.8)=20.5÷1=20.5 ④9.88×9+9.88=9.88×(9+1)=9.88×10=98.823.【解答】解:(1)12.6÷(1.02+3.18)=12.6÷4.2=3;(2)5.7×6.9+4.3×6.9=(5.7+4.3)×6.9=10×6.9=69;(3)(0.81+2.7)÷0.9=3.51÷0.9=3.9;(4)[(8.4﹣7.9)÷0.25]×1.2=[0.5÷0.25]×1.2=2×1.2=2.4.24.【解答】解:(1)25×1.25×32 =25×1.25×8×4=(25×4)×(1.25×8)=100×10=1000(2)(+)×35=×35+×35=10+7=17(3)78×=(79﹣1)×=79×﹣=3﹣=2(4)÷+=÷=25.【解答】解:(1)1.6×3.9×1.25=0.8×2×3.9×1.25=(0.8×1.25)×(2×3.9)=1×7.8=7.8(2)4.87×2.34+48.7×0.266=4.87×2.34+4.87×2.66=4.87×(2.34+2.66)=4.87×5=24.35(3)0.49×9.9 =0.49×(10﹣0.1)=0.49×10﹣0.49×0.1=4.9﹣0.049=4.851(4)0.05×0.7×20×1.7=(0.05×20)×(0.7×1.7)=1×1.19=1.19(5)2.5×3.2×12.5 =2.5×0.4×8×12.5 =(2.5×0.4)×(8×12.5)=1×100=100(6)3.95×7.6+3.95×3.4﹣3.95=3.95×(7.6+3.4﹣1)=3.95×10=39.5 26.【解答】解:(1)7.8×6.9+2.2×6.9=(7.8+2.2)×6.9=10×6.9=69(2)2.36×2.5×4=2.36×(2.5×4)=2.36×10=23.6(3)102×0.45=(100+2)×0.45=100×0.45+2×0.45=45+0.9=45.9(4)4.19×99+4.19=4.19×(99+1)=4.19×100=419(5)21.36÷0.8﹣12.9=26.7﹣12.9=13.8(6)3.2÷0.8×0.26=4×0.26=1.0427.【解答】解:(1)6.33×101﹣6.33=6.33×(101﹣1)=6.33×100=633;(2)1.6×55.4﹣55.4×0.6=(1.6﹣0.6)×55.4=1×55.4=55.4;(3)17.68÷5.2+2.7×1.5=3.4+4.05=7.45;(4)(1.1﹣0.78)×(2.7﹣1.95)=0.32×0.75=0.24;(5)35.6﹣5×1.73=35.6﹣8.65=26.95;(6)15÷0.2÷2.5=15÷(0.2×2.5)=15÷0.5=30.28.【解答】解:(1)2.5×1.37×0.4=2.5×0.4×1.37=1×1.37=1.37;(2)4.8×0.25×25=(4×4×0.3)×0.25×25=(4×0.25)×(4×25)×0.3=1×100×0.3=30;(3)0.89×4.8+0.89×5.2=0.89×(4.8+5.2)=0.89×10=8.9;(4)101×0.78×20=101×(0.78×20)=101×15.6=(100+1)×15.6=100×15.6+1×15.6=1560+15.6=1575.6;(5)8.8×1.25×15=(8×1.1)×1.25×15=(8×1.25)×(1.1×15)=10×16.5=165;(6)4.3×0.8×5=4.3×(0.8×5)=4.3×4=17.2.29.【解答】解:(1)44.28÷0.9÷4.1=49.2÷4.1=12;(2)0.25×0.39×4=(0.25×4)×0.39=1×0.39=0.39;(3)7.6+7.6×99=7.6×(1+99)=7.6×100=760;(4)9.07﹣22.78÷3.4=9.07﹣6.7=2.37;(5)4.8×99+4.8=4.8×(99+1)=4.8×100=480;(6)6.3×10.1=6.3×(10+0.1)=6.3×10+6.3×0.1=63+0.63=63.63.30.【解答】解:(1)5.8+3.8×0.25=5.8+0.95=6.75(2)1.7×(4.65﹣3.87)=1.7×0.78=1.326(3)1.25×4.3×0.8=1.25×0.8×4.3=1×4.3=4.3(4)4.5×102=4.5×(100+2)=4.5×100+4.5×2=450+9=459(5)0.54×101﹣0.54=0.54×(101﹣1)=0.54×100=54(6)3.4×2.5+6.6×2.5=(3.4+6.6)×2.5=10×2.5=2531.【解答】解:①0.45×12×0.2=0.45×0.2×12=0.09×12=1.08②6.2×2.1﹣2.1 =2.1×(6.2﹣1)=2.1×5.2=10.92 ③0.9×0.8×100=0.72×100=72④2.8﹣2.8×0.15 =2.8×(1﹣0.15)=2.8×0.85=2.38 ⑤2.8×1.43+0.57 =4.004+0.57=4.574⑥72×0.81+10.3=58.32+10.3=68.62⑦10﹣6.06+8.5=3.94+8.5=12.44⑧6×0.25×1.8 =1.5×1.8=2.7⑨7.06×2.4﹣5.8 =16.944﹣5.8=11.14432.【解答】解:(1)0.25×9.87×4 =0.25×4×9.87=1×9.87=9.87;(2)36.2×1.8+13.8×1.8 =(36.2+13.8)×1.8=50×1.8=90;(3)0.125×2.3×8=0.125×8×2.3=1×2.3=2.3;(4)0.73×102 =0.73×(100+2)=0.73×100+0.73×2=73+1.46=74.46;(5)(6.8+2.6)×5 =6.8×5+2.6×5=34+13=47;(6)0.23×98=0.23×(100﹣2)=0.23×100﹣0.23×2=23﹣0.46=22.54.33.【解答】解:(1)12.5×32×2.5 =12.5×4×8×2.5=(12.5×8)×(2.5×4)=100×10=1000;(2)6.8×9.9 =6.8×(10﹣0.1)=6.8×10﹣6.8×0.1=68﹣0.68=67.32;(3)7.2÷[1.8×(3.4﹣2.9)]=7.2÷[1.8×0.5]=7.2÷0.9=8.34.【解答】解:(1)3.4×9+3.4=30.6+3.4=34;(2)6.4÷0.8﹣1.5×4=8﹣6=2;(3)3.78÷0.25÷4=3.78÷(0.25×4)=3.78÷1=3.78;(4)17÷[(1.2+0.5)×5]=17÷[1.7×5]=17÷8.5=2.35.【解答】解:(1)2.5×1.25×8×0.4 =(2.5×0.4)×(1.25×8)=1×10=10;(2)12.8×1.7+87.2×1.7 =(12.8+87.2)×1.7=100×1.7=170;(3)100﹣4.35﹣5.65=100﹣(4.35+5.65)=100﹣10=90.36.【解答】解:(1)4+7.6×15 =4+114=118;(2)26.08÷0.25÷4=26.08÷(0.25×4)=26.08÷1=26.08;(3)19.7+(80.5÷35×0.2)=19.7+(2.3×0.2)=19.7+0.46=20.16.37.【解答】解:(1)1.25×2.25×0.8=1.25×0.8×2.25=1×2.25=2.25;(2)9.7×99+9.7=9.7×(99+1)=9.7×100=970;(3)4.8×7.8+78×0.52=4.8×7.8+7.8×5.2=(4.8+5.2)×7.8=10×7.8=78;(4)3.65×10.1=3.65×(10+0.1)=3.65×10+3.65×0.1=36.5+0.365=36.865.38.【解答】解:①12.36﹣6.49﹣3.51=12.36﹣(6.49+3.51)=12.36﹣10=2.36;②8.5×3.8+8.5×6.2=8.5×(3.8+6.2)=8.5×10=85;③17.3×0.25×8=17.3×(0.25×8)=17.3×2=34.6;④15.32﹣1.8×5﹣3.46=15.32﹣9﹣3.46=6.32﹣3.46=2.86;⑤199×2.6=(200﹣1)×2.6=200×2.6﹣1×2.6=520﹣2.6=517.4;⑥3.6÷[(1.3+0.6)×5]=3.6÷[1.9×5]=3.6÷9.5=.39.【解答】解:(1)8.5+6.85﹣6.35 =8.5+(6.85﹣6.35)=8.5+0.5=9;(2)3.9+0.1﹣3.9+0.1 =(3.9﹣3.9)+(0.1+0.1)=0+0.2=0.2;(3)12.6﹣(3.75+5.08)=12.6﹣8.83=3.77.40.【解答】解:(1)6.09﹣9.13÷8.3=6.09﹣1.1=4.99(2)3.84×9.6+0.96×61.6 =(3.84+6.16)×9.6=10×9.6=96(3)4.86×99=4.86×(100﹣1)=4.86×100﹣4.86=486﹣4.86=481.14(4)5.68×4+4.32÷0.25 =5.68×4+4.32×4=(5.68+4.32)×4=10×4=40(5)6.4×4.5+3.6×4.5=(6.4+3.6)×4.5=10×4.5=4541.【解答】解:①10.5+61×18=10.5+1098=1108.5 ②(3.14+12.6)÷8=15.74÷8=1.9675③4.5÷(15÷3)=4.5÷5=0.9④75+448÷4×19=75+112×19=75+2128=220342.【解答】解:(1)(18.5×3.8+3.8×2.5)÷0.19 =3.8×(18.5+2.5)÷0.19 =3.8×21÷0.19=3.8÷0.19×21=200×21=4200(2)[32﹣(7.25+0.75×8)]÷50=[32﹣(7.25+6)]÷50=[32﹣13.25]÷50=18.75÷50=0.37543.【解答】解:①25.32﹣(3.4﹣1.2)=25.32﹣2.2=23.12②12﹣0.62﹣4.38=12﹣(0.62+4.38)=12﹣5=7 44.【解答】解:(1)5.12+2.54+4.88=5.12+4.88+2.54=10+2.54=12.54;(2)12.5×17.8×0.8=12.5×0.8×17.8=10×17.8=178;(3)0.24×0.48×4=0.1152×4=0.4608;(4)9.9×2.5=(10﹣0.1)×2.5=10×2.5﹣0.1×2.5=25﹣0.25=24.75;(5)9.4×5.8+10.6×5.8=(9.4+10.6)×5.8=20×5.8=116;(6)0.66×101=0.66×(100+1)=0.66×100+0.66×1=66+0.66=66.66;(7)4.8×0.25=(1.2×4)×0.25=1.2×(4×0.25)=1.2×1=1.2;(8)2.33×0.5×4 =2.33×(0.5×4)=2.33×2=4.66;(9)1.3×2.5+0.7×2.5=(1.3+0.7)×2.5=2×2.5=5;(10)1.26×0.6+1.26×0.4=1.26×(0.6+0.4)=1.26×1=1.26;(11)102×0.55=(100+2)×0.55=100×0.55+2×0.55=55+1.1=56.1;(12)0.034×0.5×0.2=0.034×(0.5×0.2)=0.034×0.1=0.0034.45.【解答】解:(1)13.38+0.98=13.38+(1﹣0.02)=13.38+1﹣0.02=14.38﹣0.02=14.36;(2)7.02﹣2.98 =7.02﹣(3﹣0.02)=7.02﹣3+0.02 =4.02+0.02=4.04;(3)6.57﹣(0.68﹣0.39+0.32)=6.57﹣(0.68+0.32﹣0.39)=6.57﹣(1﹣0.39)=6.57﹣0.61=5.96;(4)13.8÷(1.38×0.2)=13.8÷1.38÷0.2=10÷0.2=50;(5)30.7﹣0.12×2﹣0.76 =30.7﹣0.24﹣0.76=30.7﹣(0.24+0.76)=30.7﹣1=29.7;(6)7.8×1.01=7.8×(1+0.01)=7.8×1+7.8×0.01=7.8+0.078=7.878;(7)18.4﹣6.5+1.6+3.5 =(18.4+1.6)﹣(6.5﹣3.5)=20﹣3=17;(8)7.8÷0.6+7.8÷0.4=13+19.5=32.5;(9)12.13+7.5﹣1.13+2.85=(12.13﹣1.13)+(7.5+2.85)=11﹣10.35=0.65;(10)0.125×8.8=0.125×(8+0.8)=0.125×8+0.125×0.8=1+0.1=1.1;(11)9.4×3.2+6×0.32 =9.4×3.2+0.6×3.2=(9.4+0.6)×3.2=10×3.2=32;(12)9.6×3.6+7.2×0.2=9.6×3.6+3.6×2×0.2=9.6×3.6+3.6×0.4=(9.6+0.4)×3.6=10×3.6=36.46.【解答】解:(1)96÷(100×0.48)=96÷48=2;(2)3.6÷(1.2+0.5)×6=3.6÷1.7×6=×6=;(3)(967﹣31)÷(17+48)=936÷65=14.4;(4)72×10.1+27×10.1=(72+27)×10.1=99×10.1=99×(10+0.1)=99×10+99×0.1=990+9.9=999.9.47.【解答】解:(1)3.4×7.8÷3.9=26.52÷3.9=6.8;(2)54÷(3.94+6.86)=54÷10.8=5.48.【解答】解:①0.486+0.01+3.99 =0.486+(0.01+3.99)=0.486+4=4.486 ②17.5×2.3﹣7.5×2.3 =2.3×(17.5﹣7.5)=2.3×10=23 ③1.25×11×4×0.8=(1.25×0.8)×(11×4)=1×44=44④4.8×39+61×4.8=4.8×(39+61)=4.8×100=480 ⑤45.55﹣(6.82+15.55)=45.55﹣6.82﹣15.55=45.55﹣15.55﹣6.82=30﹣6.82=23.18⑥3.2×99+3.2=3.2×(99+1)=3.2×100=320⑦2.5×56+4.5×56 =56×(2.5+4.5)=56×7=392⑧(31.6﹣11.7)÷2.5÷4 =19.9÷(2.5×4)=19.9÷10=1.99⑨3.6×0.9+3.6×0.1=3.6×(0.9+0.1)=3.6×1=3.649.【解答】解:(1)7.5﹣2.4÷0.8×2.5 =7.5﹣3×2.5=7.5﹣7.5=0;(2)12.5×17+83×12.5=12.5×(17+83)=12.5×100=1250;(3)399×2.5 =(400﹣1)×2.5=400×2.5﹣2.5=1000﹣2.5=997.25;(4)25÷(2.5÷0.4)=25÷2.5×0.4=10×0.4=4;(5)3.25×67+5.75×67+67 =(3.25+5.75+1)×67=10×67=670;(6)230÷2.5×7.5=92×7.5=690;(7)6.3+0.84+3.7+8.16=(6.3+3.7)+(0.84+8.16)=10+9=19;(8)100﹣(2.72+10.8)÷0.2=100﹣13.52÷0.2=100﹣67.6=32.4.50.【解答】解:(1)0.25×3.25×4=0.25×4×3.25=1×3.25=3.25(2)6.72+3.2÷2.5=6.72+1.28=8(3)21.36÷0.4﹣23.4=53.4﹣23.4=30(4)0.8×4.5+1.2×4.5=(0.8+1.2)×4.5=2×4.5=9。

小数的连除、除加、除减混合运算和简便算法_五年级数学教案_模板

小数的连除、除加、除减混合运算和简便算法_五年级数学教案_模板

小数的连除、除加、除减混合运算和简便算法_五年级数学教案_模板教学目标1.掌握小数连除、除加、除减的运算顺序,会正确计算,并能根据题目的特点对一些小数除法进行正确的简算.2.通过对小数连除、除加、除减的运算顺序的归纳,提高学生的抽象概括能力.3.培养学生养成良好的学习习惯,提高学生的计算能力.教学重点小数连除、除加、除减的运算顺序.教学难点小数除法的简算.教学过程()一、复习准备(一)口算0.8×0.5 1.6+0.38 0.15÷5 1-0.750.48÷0.03 630÷45÷2 6÷1.2 4×2.5280÷35 0.56÷14 0.92÷0.4 1.1×5教师提问:630÷45÷2 280÷35 0.56÷14是怎样口算的?为新知辅垫(二)先想一想下面各题的运算顺序,再计算.360÷4÷5 420÷6+150 750÷5-80二、探索新知(一)教学连除、除加、除减混合运算.例10.一只蜜蜂0.5小时飞行9.3千米,是一只蝴蝶飞行速度的2.4倍.这只蝴蝶每小时飞行多少千米?1.分析数量关系并列式9.3÷0.5÷2.4教师提问:9.3÷0.5求的是什么?2.尝试计算说一说运算顺序,先算什么?再算什么?3.练一练432÷3.6+2.88 2.96÷0.4-1.73教师提问:小数连除、除加、除减的运算顺序是什么?它与整数连除、除加、除减有什么联系?结论:小数连除、除加、除减的运算顺序与整数完全相同.(二)小数除法的一些简便算法1.教师:在整数除法中,我们学过了一些简便算法.360÷45÷2 560÷35教师提问:谁能说一说这两道题怎样算比较简便?2.变式3.6÷4.5÷25.6÷35(1)学生独立完成,指名板演.(2)集体订正,说出简算的方法.小结:整数除法中的简算方法在小数除法中了同样适用.3.做一做,用简便方法计算4.5÷18 930÷5÷0.6三、课堂小结1.从这节课中你知道了什么?2.对于今天学习的知识还有什么问题或疑惑?四、巩固新知(一)在下面的□里填上适当的数.2.1÷28=2.1÷□÷□0.78÷0.3÷0.2=0.78÷□(二)计算下面各题.(能简算的要简算)213.6÷0.8÷0.3 0.77÷3540.5÷0.5+10.75 9.728÷3.2÷197.2÷1.2÷3 18.305÷0.07÷85.76(三)对比练习13.4÷4÷2.5 35×1.6÷810.8÷3.3 3.2+0.128÷0.8(四)看算式直接写得数0.25×2.3×4 1.5÷1.5+1.5 1-0.32-0.681.4×0.5-0.7 4.5÷4.5÷2 18.4÷4÷2.33.6-2.4÷2.4 50×0.34×0.2 20×(0.1-0.05)0.1×0.2×0.3 4.6×7+3×4.6 38.5×0×0.381.25×0.4×8 0.65×101 0.5×4÷0.5×4五、板书设计小数连除、除加、除减例10.一只蜜蜂0.5小时飞行9.3千米,是一只蝴蝶飞行速度的2.4倍.这只蝴蝶每小时飞行多少千米?9.3÷0.5÷2.4=18.6÷2.4=7.75(千米)答:这只蝴蝶每小时飞行7.75千米.《长方体和正方体的表面积》教案设计一、教学构思长方体和正方体是学生十分熟悉的立体图形,在生活中经常要求解它们的表面积,例如:计算做一个长方体形状的鱼缸需要多少材料。

小数除法的简便计算

小数除法的简便计算

小数除法的简便计算小数除法是数学中很常见的一种运算方法,它可以用于解决很多实际问题和数学推导。

虽然小数除法可以通过手算进行近似计算,但对于一些较长的小数,手算往往会非常繁琐,容易出错。

因此,为了简化小数除法的计算过程,我们可以采用一些简便的方法,如下所示。

1.简化除数:当除数为小数时,我们可以通过移动小数点的位置,将除数转化为整数。

方法是将除数与被除数中的小数点向右移动相同的位数,保持二者的比值不变。

然后将被除数除以简化后的除数即可。

例如:计算12.5÷0.25,可以将除数0.25转化为整数25,同时将被除数12.5中的小数点向右移动两位,得到125、然后计算125÷25=5,因此结果为52.估算商值:对于一些较长的小数除法,我们可以通过估算商值,进行近似计算。

方法是先忽略小数点,将被除数和除数看作整数,然后计算其商值。

最后根据小数点的位数对计算结果进行调整。

例如:计算3.56÷0.08,可以将被除数3.56和除数0.08都看作整数,即356÷8、通过估算得到商值为44,然后将小数点向左移动两位,得到44.00。

因此结果为44.00。

3.使用倍数关系:当两个小数存在倍数关系时,可以通过简单的乘法和除法运算得到结果。

方法是将除数和被除数都乘以一个合适的倍数,使得两者之一成为整数。

然后计算简化后的除法。

例如:计算0.6÷0.03,可以将被除数0.6乘以100,得到60,将除数0.03乘以100,得到3、然后计算60÷3=20,因此结果为20。

4.使用除数规律:当除数为重复的小数时,可以推导出它的一些规律,从而简化计算过程。

方法是通过观察和分析,找出重复的部分,并将其转化为无限循环小数的形式。

然后计算有限小数部分的值。

例如:计算0.3÷0.27,可以观察到除数0.27是重复的小数,因此可以将其转化为无限循环小数的形式。

计算得到0.27=0.2+0.07=0.2+7×0.01、然后计算得到0.3÷0.2=1.5,0.3÷0.01=30。

小数除法及简算26份

小数除法及简算26份
4.78÷4.76○125.8÷1.05○25.8 24.7÷0.95○24.7
练习3、(36-1.8-8.1)÷0.9 230÷3.6+130÷3.6
练习4、48.3÷(4.83÷0.17)37.5÷(2.5÷2)
练习5、24.60÷0.5÷22250÷7.5÷3
巩固提高:
99÷2.5-40÷2.5-34÷2.514.8÷4÷0.25
课 题
第二讲 小数除法及简算
主备
课时安排
学习目标
1、熟练掌握小数除法的方法。2、掌握商不变原理、有余数的除法及简便除法
热身运动:
1、2.56÷0.6表示:。
ቤተ መጻሕፍቲ ባይዱ0.76÷8表示:。
2、列竖式计算上面两道题并验算。
例题1:10÷3=( )…( ) 100÷30=( )…( ) 1000÷300=( )…( )
如果A÷5=B…2,被除数和除数同时扩大100倍,那么除数=( ),余数=( )
例题2:不计算迅速填上大于号或小于号
6.04÷7○145÷76.5○16.04÷0.95○6.04
8.42÷7○16.04÷1.05○6.04 3.78÷0.89○3.78
我的发现:。
例题3:(100-88-8.8)÷0.8(100+12.5)÷12.5
课后作业:
137÷2.5+113÷2.52006÷1.1-400÷1.1-500÷1.1
48.3÷(4.83÷0.17)765×21.3÷27+765×32.7÷27
我的收获:

家校直通车:孩子做作业时间 : ------- : 。
家长意见:
家长签字:
例题4、98.7÷(98.7÷0.24)1250÷(10÷0.8)

(完整)小数除法脱式运算+简算260道含答案(2),推荐文档

(完整)小数除法脱式运算+简算260道含答案(2),推荐文档

小数除法脱式运算+简算260道一.计算题(共50小题)1.用你喜欢的方法计算.32×12.5×0.25 6.1×4.2+5.8×6.1 1.7÷2.5÷0.416.1﹣4.2﹣5.8.3.脱式计算4.8÷(1.2÷0.5)12.8﹣12.8÷571.4÷(7×6)4.用你喜欢的方法计算0.65×101﹣0.65 12.6﹣3.25+6.756.35÷0.2÷0.5 5.7×1.2÷19 1.25×3.63×0.8.5.我能用喜欢的方法计算下面各题.0.11×1.8+8.2×0.11 3.5﹣3.5×0.980.75×18÷0.150.25×4.78×8.6.能简算的要简算.17.3÷0.125÷8 14.72×0.7+5.28×0.73.5÷0.56 8.5×9.9+0.82.7.递等式计算,有简便运算的用简便方法38.75﹣(24.5+8.75)0.4×2.32×0.250.75×101 4.2﹣3.2×0.97.56×99+7.5670.3﹣17.48÷7.6 3.64÷5.2×23.321.8÷0.8﹣1.2×5 45÷(5.25÷0.25)16.5×101﹣16.50.96÷0.3×14 1.25×4×2.5×836.45÷(0.82+3.4×0.2)9.07﹣2.64÷0.4 1.5×10112.6×7.5+8.3 13.6×0.85﹣3.6×0.85104×8.586.4÷6.4﹣0.40.25×6.2×0.4 23×6.5+17×6.536÷0.4×0.25(24.6﹣18.1)×3.47.6×9.9+7.6×0.113.6×0.8×12.523.9×8.5﹣3.9×8.5(2.55+9.6÷16)÷0.429.2÷0.25÷48.脱式计算(能简算的要简算)0.75×4×0.25×49.6+9.9×9915.58÷8.2﹣0.724.536÷0.8÷14 2.8×3.6+1.4×2.8 6.3×10.1.9.脱式计算(能简算的要用简算)4.2×7.8+2.2×4.2 9.5×101(8×3.82)×1.25 0.125×720.6×3.9×0.8 42×0.39+4.2×6.110.脱式计算,能简算的要简算0.25×1.25×1618.9﹣18.9÷1.48.37×1.2﹣8.37×0.243×11.8+5.7×118.11.用简便方法计算.6.2+5.18+2.8 15.35﹣(5.35+7.2)3.63﹣1.25+17.37﹣8.75 51.72﹣8.66﹣1.34.12.脱式计算,能简算的要简算.0.7×101﹣0.7 0.125×4.95×8 12.9﹣1.68﹣2.32 567÷20÷5.13.用递等式计算,能简算的要简算.20.16÷7.2+9.8 6.2×2.7+6.5×7.3 32.8+9.6+7.2.14.脱式计算:能简算的要简算15.89﹣(5.89+6.98)0.25×13.7×0.432.7×28+7.3×2815×9.4﹣42 4.9+12.87﹣5.380.05×0.7×20×1.7.15.计算下面各题,能简算的要简算.5.04×28(15.4﹣7.8)×3.5 3.2×4.6+3.2×5.40.25×17.4×4 20﹣6.72﹣3.28 8.33+7.45+1.67+2.55 16.脱式计算.0.2×0.6×0.5×4 (7.5﹣2.3×0.4)÷0.011.2×0.25+2.8×0.25 178.8÷(26.4﹣5.6)17.能简算的要简算3.6﹣1.28+3.09 3.82+2.9+0.18+9.1 9.43﹣(6.28﹣1.57)21.32﹣(6.32+8.3)13.75﹣(3.75+6.48)15﹣7.35﹣2.6518.混合运算,能简便就简便19.81﹣2.68﹣8.32 5.6+6.6﹣5.6+6.60.81×27+0.19×27101×0.19﹣0.19.19.用简便方法计算9.08﹣1.76﹣4.24 18.38﹣(5.38+1.8)﹣8.217.45﹣(8.76﹣6.55)12.87+3.98﹣3.87.20.脱式计算,能简便的用简便方法计算.10.8÷(3.94+6.86)×0.8 0.65×201 12.5×3.9×0.839.8×0.25×4 37.6×8+37.6×2 0.78×99+0.78.21.脱式计算:21.8﹣7.22﹣2.78 9﹣0.24÷1.6×1.19.12+9.12×9﹣6.02 45.2×66.7+66.7×53.8+66.70.25×0.8×0.125×0.4 12.75÷[14.6﹣(1.3+8.2)]0.125×36×(4÷0.5)÷36[(6.1﹣4.6)×0.8﹣1]×0.3615.6﹣(4.1+0.2+6.86÷0.7)[5﹣(1﹣1.2×0.8)]÷41÷0.25+0.4×0.6 13.6×3﹣40.6÷2 25.8+10.5÷(5﹣3.5) 1.42﹣0.36÷6×0.6 49.5×0.2﹣2.07÷23 6.7+3.3÷4.4+5.622.计算下面各题(能简算的要简算)50×(0.8+0.4)7.34×2.1+7.34×6.8+7.34×1.120.5÷1.25÷0.8 9.88×9+9.88.23.计算下列各题(能用简便算法的要用简便算法).12.6÷(1.02+3.18) 5.7×6.9+4.3×6.9(0.81+2.7)÷0.9[(8.4﹣7.9)÷0.25]×1.2.25.能简算的用简便方法计算.(写出主要简便过程,无过程不得分)1.6×3.9×1.25 4.87×2.34+48.7×0.2660.49×9.9 0.05×0.7×20×1.72.5×3.2×12.5 3.95×7.6+3.95×3.4﹣3.95.26.计算下面各题,能简算的要简算7.8×6.9+2.2×6.9 2.36×2.5×4102×0.454.19×99+4.1921.36÷0.8﹣12.9 3.2÷0.8×0.2627.计算(能简算的要简算).6.33×101﹣6.33 1.6×55.4﹣55.4×0.617.68÷5.2+2.7×1.5(1.1﹣0.78)×(2.7﹣1.95)35.6﹣5×1.7315÷0.2÷2.528.脱式计算(能简算的要简算)2.5×1.37×0.4 4.8×0.25×250.89×4.8+0.89×5.2 101×0.78×208.8×1.25×15 4.3×0.8×529.计算下面各题,能简算的要简算.44.28÷0.9÷4.10.25×0.39×47.6+7.6×99 9.07﹣22.78÷3.4 4.8×99+4.8 6.3×10.1 30.下面各题,能简算的就要简算.5.8+3.8×0.25 1.7×(4.65﹣3.87) 1.25×4.3×0.84.5×1020.54×101﹣0.54 3.4×2.5+6.6×2.5.31.计算下列各题.0.45×12×0.2 6.2×2.1﹣2.1 0.9×0.8×1002.8﹣2.8×0.15 2.8×1.43+0.57 72×0.81+10.310﹣6.06+8.5 6×0.25×1.8 7.06×2.4﹣5.832.用简便方法计算.0.25×9.87×4 36.2×1.8+13.8×1.8 0.125×2.3×80.73×102 (6.8+2.6)×5 0.23×98.33.能用简便方法的用简便方法计算12.5×32×2.5 6.8×9.9 7.2÷[1.8×(3.4﹣2.9)].34.用你喜欢的方法计算.3.4×9+3.4 6.4÷0.8﹣1.5×4 3.78÷0.25÷4 17÷[(1.2+0.5)×5].35.用你喜欢的方法计算2.5×1.25×8×0.4 12.8×1.7+87.2×1.7 100﹣4.35﹣5.65.36.用递等式计算(能简算的要简算).4+7.6×15 26.08÷0.25÷419.7+(80.5÷35×0.2)37.计算,能简算的要简算.1.25×2.25×0.8 9.7×99+9.7 4.8×7.8+78×0.523.65×10.1.38.计算下面各题.(能简算的用简便算法)①12.36﹣6.49﹣3.51②8.5×3.8+8.5×6.2③17.3×0.25×8④15.32﹣1.8×5﹣3.46⑤199×2.6⑥3.6÷[(1.3+0.6)×5]39.计算8.5+6.85﹣6.35 3.9+0.1﹣3.9+0.1 12.6﹣(3.75+5.08)40.计算,能简算的要简算6.09﹣9.13÷8.3 3.84×9.6+0.96×61.6 4.86×995.68×4+4.32÷0.256.4×4.5+3.6×4.5.41.脱式计算.10.5+61×18 (3.14+12.6)÷8 4.5÷(15÷3)75+448÷4×19.42.计算:(18.5×3.8+3.8×2.5)÷0.19 [32﹣(7.25+0.75×8)]÷50.43.脱式计算,能简算的就简算:25.32﹣(3.4﹣1.2)12﹣0.62﹣4.38.44.用简便方法计算下面各题.5.12+2.54+4.88 12.5×17.8×0.8 0.24×0.48×49.9×2.5 9.4×5.8+10.6×5.8 0.66×101 4.8×0.25 2.33×0.5×4 1.3×2.5+0.7×2.5 1.26×0.6+1.26×0.4 102×0.55 0.034×0.5×0.245.计算.(怎样简便就怎么计算)13.38+0.98=7.02﹣2.98 6.57﹣(0.68﹣0.39+0.32)13.8÷(1.38×0.2)30.7﹣0.12×2﹣0.76 7.8×1.0118.4﹣6.5+1.6+3.5 7.8÷0.6+7.8÷0.412.13+7.5﹣1.13+2.85 0.125×8.89.4×3.2+6×0.32 9.6×3.6+7.2×0.2.46.计算下面各题,能简算得要简算.96÷(100×0.48) 3.6÷(1.2+0.5)×6(967﹣31)÷(17+48)72×10.1+27×10.1.47.用自己喜欢的方法计算.3.4×7.8÷3.9 54÷(6.86+3.94)48.用简便方法计算0.486+0.01+3.99 17.5×2.3﹣7.5×2.3 1.25×11×4×0.84.8×39+61×4.8 45.55﹣(6.82+15.55) 3.2×99+3.22.5×56+4.5×56 (31.6﹣11.7)÷2.5÷43.6×0.9+3.6×0.149.计算下列各题.(能简算的要简算)7.5﹣2.4÷0.8×2.5 12.5×17+83×12.5399×2.5 25÷(2.5÷0.4)3.25×67+5.75×67+67 230÷2.5×7.5 6.3+0.84+3.7+8.16 100﹣(2.72+10.8)÷0.250.脱式计算0.25×3.25×4 6.72+3.2÷2.521.36÷0.4﹣23.40.8×4.5+1.2×4.5.小数除法脱式运算+简算260道参考答案与试题解析 一.计算题(共50小题)1.【解答】解:(1)32×12.5×0.25=4×8×12.5×0.25=(4×0.25)×(8×12.5)=1×100=100(2)6.1×4.2+5.8×6.1=6.1×(4.2+5.8)=6.1×10=61(3)1.7÷2.5÷0.4=1.7÷(2.5×0.4)=1.7÷1=1.7(4)16.1﹣4.2﹣5.8=16.1﹣(4.2+5.8)=16.1﹣10=6.1 2.【解答】解:(1)(0.6×0.8+0.12)÷1.2=0.6÷1.2=0.5答:商是0.5.(2)(14.81+5.19)×(14.81﹣5.19)=20×9.62=192.4答:积是192.4.(3)[(2.7+4.5)÷12]×0.3=[7.2÷12]×0.3=0.6×0.3=0.18答:积是0.18. 3.【解答】解:①4.8÷(1.2÷0.5)=4.8÷2.4=2②12.8﹣12.8÷5=12.8﹣2.56=10.24③71.4÷(7×6)=71.4÷7÷6=10.2÷6=1.7 4.【解答】解:①0.65×101﹣0.65=0.65×(101﹣1)=0.65×100=65②12.6﹣3.25+6.75=12.6+(6.75﹣3.25)=12.6+3.5=16.1③6.35÷0.2÷0.5=6.35÷(0.2×0.5)=6.35÷0.1=63.5④5.7×1.2÷19=5.7÷19×1.2=0.3×1.2=0.36⑤1.25×3.63×0.8=(1.25×0.8)×3.63=1×3.63=3.63 5.【解答】解:①0.11×1.8+8.2×0.11=0.11×(1.8+8.2)=0.11×10=1.1②3.5﹣3.5×0.98=3.5×(1﹣0.98)=3.5×0.02=0.07③0.75×18÷0.15=0.75÷0.15×18=5×18=90④0.25×4.78×8=0. 25×8×4.78=2×4.78=9.56 6.【解答】解:①17.3÷0.125÷8=17.3÷(0.125×8)=17.3÷1=17.3②14.72×0.7+5.28×0.7=(14.72+5.28)×0.7=20×0.7=14③3.5÷0.56=(3.5÷0.7)÷(0.56÷0.7)=5÷8=0.625④8.5×9.9+0.82=8.5×(10﹣0.1)+0.82=8.5×10﹣8.5×0.1+0.82=85﹣0.85+0.82=85﹣(0.85﹣0.82)=85﹣0.03=84.97 7.【解答】解:(1)38.75﹣(24.5+8.75)=38.75﹣24.5﹣8.75=38.75﹣8.75﹣24.5=30﹣24.5=5.5;(2)0.4×2.32×0.25=0.4×0.25×2.32=0.1×2.32=0.232;(3)0.75×101=0.75×(100+1)=0.75×100+0.75×1=75+0.75=75.75;(4)4.2﹣3.2×0.9=4.2﹣2.88=1.32;(5)7.56×99+7.56=7.56×(99+1)=7.56×100=756;(6)70.3﹣17.48÷7.6=70.3﹣2.3=68;(7)3.64÷5.2×23.3=0.7×23.3=16.31;(8)21.8÷0.8﹣1.2×5=27.25﹣6=21.25;(9)45÷(5.25÷0.25)=45÷21=;(10)16.5×101﹣16.5=16.5×(101﹣1)=16.5×100=1650;(11)0.96÷0.3×14=3.2×14=44.8;(12)1.25×4×2.5×8=(1.25×8)×(4×2.5)=10×10=100;(13)36.45÷(0.82+3.4×0.2)=36.45÷(0.82+0.68)=36.45÷1.5=24.3;(14)9.07﹣2.64÷0.4=9.07﹣6.6=2.47;(15)1.5×101=1.5×(100+1)=1.5×100+1.5×1=150+1.5=151.5;(16)12.6×7.5+8.3=94.5+8.3=102.8;(17)13.6×0.85﹣3.6×0.85=(13.6﹣3.6)×0.85=10×0.85=8.5;(18)104×8.5=(100+4)×8.5=100×8.5+4×8.5=850+34=884;(19)86.4÷6.4﹣0.4=13.5﹣0.4=13.1;(20)0.25×6.2×0.4=0.25×0.4×6.2=0.1×6.2=0.62;(21)23×6.5+17×6.5=(23+17)×6.5=40×6.5=260;(22)36÷0.4×0.25=90×0.25=22.5;(23)(24.6﹣18.1)×3.4=6.5×3.4=22.1;(24)7.6×9.9+7.6×0.1=7.6×(9.9+0.1)=7.6×10=76;(25)13.6×0.8×12.5=13.6×(0.8×12.5)=13.6×10=136;(26)23.9×8.5﹣3.9×8.5=(23.9﹣3.9)×8.5=20×8.5=170;(27)(2.55+9.6÷16)÷0.42=(2.55+0.6)÷0.42=3.15÷0.42=7.5;(28)9.2÷0.25÷4=9.2÷(0.25×4)=9.2÷1=9.2. 8.【解答】解:(1)0.75×4×0.25×4=(0.75×4)×(0.25×4)=3×1=3(2)9.6+9.9×99=9.6+9.9×(100﹣1)=9.6+9.9×100﹣9.9=9.6+990﹣9.9=989.7(3)15.58÷8.2﹣0.72=1.9﹣0.72=1.18(4)4.536÷0.8÷14=5.67÷14=0.405(5)2.8×3.6+1.4×2.8=2.8×(3.6+1.4)=2.8×5=14(6)6.3×10.1=6.3×(10+0.1)=6.3×10+6.3×0.1=63+0.63=63.63 9.【解答】解:(1)4.2×7.8+2.2×4.2=4.2×(7.8+2.2 )=4.2×10=42(2)9.5×101=9.5×(100+1)=9.5×100+9.5=950+9.5=959.5(3)(8×3.82)×1.25 =(8×1.25)×3.82=10×3.82=38.2(4)0.125×72=0.125×8×9=1×9=9(5)0.6×3.9×0.8 =2.34×0.8=1.872(6)42×0.39+4.2×6.1=42×0.39+42×0.61=42×(0.39+0.61)=42×1=42 10.【解答】解:(1)0.25×1.25×16=0.25×1.25×(2×8)=(0.25×2)×(1.25×8)=0.5×10=5(2)18.9﹣18.9÷1.4=18.9﹣13.5=5.4(3)8.37×1.2﹣8.37×0.2=8.37×(1.2﹣0.2)=8.37×1=8.37(4)43×11.8+5.7×118=43×11.8+57×11.8=(43+57)×11.8=100×11.8=1180 11.【解答】解:(1)6.2+5.18+2.8 =6.2+2.8+5.18 =9+5.18=14.18 (2)15.35﹣(5.35+7.2)=15.35﹣5.35﹣7.2=10﹣7.2=2.8(3)3.63﹣1.25+17.37﹣8.75=(3.63+17.37)﹣(1.25+8.75)=21﹣10=11(4)51.72﹣8.66﹣1.34=51.72﹣(8.66+1.34)=51.72﹣10=41.72 12.【解答】解:(1)0.7×101﹣0.7 =0.7×(101﹣1)=0.7×100=70(2)0.125×4.7×8=0.125×8×4.7=1×4.7=4.7(3)12.9﹣1.68﹣2.32=12.9﹣(1.68+2.32)=12.9﹣4=8.9(4)567÷20÷5=567÷(20×5)=567÷100=5.67 13.【解答】解:①20.16÷7.2+9.8 =2.8+9.8=12.6;②6.2×2.7+6.5×7.3 =16.74+47.45=64.19;③32.8+9.6+7.2=9.6+(32.8+7.2)=9.6+40=49.6. 14.【解答】解:(1)15.89﹣(5.89+6.98)=15.89﹣5.89﹣6.98=10﹣6.98=3.02;(2)0.25×13.7×0.4=0.25×0.4×13.7=0.1×13.7=1.37;(3)32.7×28+7.3×28=(32.7+7.3)×28=40×28=1120;(4)15×9.4﹣42=141﹣42=99;(5)4.9+12.87﹣5.38=17.77﹣5.38=12.39;(6)0.05×0.7×20×1.7=0.05×20×0.7×1.7=1×0.7×1.7=0.7×1.7=1.19. 15.【解答】解:(1)5.04×28=(5+0.04)×28=5×28+0.04×28=140+1.12=141.12;(2)(15.4﹣7.8)×3.5 =7.6×3.5 =26.6;(3)3.2×4.6+3.2×5.4=3.2×(4.6+5.4)=3.2×10=32;(4)0.25×17.4×4=0.25×4×17.4=1×17.4=17.4;(5)20﹣6.72﹣3.28=20﹣(6.72+3.28)=20﹣10=10;(6)8.33+7.45+1.67+2.55=8.33+1.67+7.45+2.55=(8.33+1.67)+(7.45+2.55)=10+10=20. 16.【解答】解:(1)0.2×0.6×0.5×4 =(0.2×0.5)×(0.6×4)=0.1×2.4=0.24;(2)(7.5﹣2.3×0.4)÷0.01=(7.5﹣0.92)÷0.01=6.58÷0.01=658;(3)1.2×0.25+2.8×0.25=(1.2+2.8)×0.25=4×0.25=1;(4)178.8÷(26.4﹣5.6)=178.8÷20.8=. 17.【解答】解:(1)3.6﹣1.28+3.09=2.32+3.09=5.41(2)3.82+2.9+0.18+9.1 =(3.82+0.18)+(9.1+2.9)=4+12=16(3)9.43﹣(6.28﹣1.57)=9.43+1.57﹣6.28=11﹣6.28=4.72(4)21.32﹣(6.32+8.3)=21.32﹣6.32﹣8.3=15﹣8.3=6.7(5)13.75﹣(3.75+6.48)=13.75﹣3.75﹣6.48=10﹣6.48=3.52(6)15﹣7.35﹣2.65=15﹣(7.35+2.65)=15﹣10=5 18.【解答】解:①19.81﹣2.68﹣8.32=19.81﹣(2.68+8.32)=19.81﹣11=8.81②5.6+6.6﹣5.6+6.6=(5.6﹣5.6)+(6.6+6.6)=0+13.2=13.2③0.81×27+0.19×27=27×(0.81+0.19)=27×1=27④101×0.19﹣0.19=(101﹣1)×0.19=100×0.19=19 19.【解答】解:(1)9.08﹣1.76﹣4.24 =9.08﹣(1.76+4.24)=9.08﹣6=3.08;(2)18.38﹣(5.38+1.8)﹣8.2=18.38﹣7.18﹣8.2=11.2﹣8.2=3;(3)17.45﹣(8.76﹣6.55)=17.45﹣8.76+6.55=17.45+6.55﹣8.76=24﹣8.76=15.24;(4)12.87+3.98﹣3.87=12.87﹣3.87+3.98=9+3.98=12.98. 20.【解答】解:①10.8÷(3.94+6.86)×0.8 =10.8÷10.8×0.8=1×0.8=0.8②0.65×201 =0.65×(200+1)=0.65×200+0.65×1=130+0.65=130.65③12.5×3.9×0.8=12.5×0.8×3.9=10×3.9=39④39.8×0.25×4 =39.8×(0.25×4)=39.8×1=39.8⑤37.6×8+37.6×2 =37.6×(8+2)=37.6×10=376 ⑥0.78×99+0.78=0.78×(99+1)=0.78×100=78 21.【解答】解:(1)21.8﹣7.22﹣2.78=21.8﹣(7.22+2.78)=21.8﹣10=11.8(2)9﹣0.24÷1.6×1.1=9﹣0.15×1.1=9﹣0.165=8.835(3)9.12+9.12×9﹣6.02=9.12×(1+9)﹣6.02=9.12×10﹣6.02=91.2﹣6.02=85.18(4)45.2×66.7+66.7×53.8+66.7=(45.2+53.8+1)×66.7=100×66.7=6670(5)0.25×0.8×0.125×0.4=(0.25×0.4)×(0.125×0.8)=0.1×0.1=0.01(6)12.75÷[14.6﹣(1.3+8.2)]=12.75÷[14.6﹣9.5]=12.75÷5.1=2.5(7)0.125×36×(4÷0.5)÷36=0.125×(4÷0.5)×(36÷36)=0.125×8×1=1(8)[(6.1﹣4.6)×0.8﹣1]×0.36=[1.5×0.8﹣1]×0.36=[1.2﹣1]×0.36=0.2×0.36=0.072(9)15.6﹣(4.1+0.2+6.86÷0.7)=15.6﹣(4.1+0.2+9.8)=15.5﹣(4.1+10)=15.5﹣14.1=1.4(10)[5﹣(1﹣1.2×0.8)]÷4=[5﹣(1﹣0.96)]÷4=[5﹣0.04]÷4=4.96÷4=1.24(11)1÷0.25+0.4×0.6=4+0.24=4.24(12)13.6×3﹣40.6÷2=40.8﹣20.3=20.5(13)25.8+10.5÷(5﹣3.5)=25.8+10.5÷1.5=25.8+7=32.8(14)1.42﹣0.36÷6×0.6=1.42﹣0.36=1.07(15)49.5×0.2﹣2.07÷23=9.9﹣0.09=9.81(16)6.7+3.3÷4.4+5.6=6.7+0.75+5.6=7.45+5.6=13.05 22.【解答】解:①50×(0.8+0.4)=50×0.8+50×0.4=40+20=60②7.34×2.1+7.34×6.8+7.34×1.1=7.34×(2.1+6.8+1.1)=7.34×10=73.4③20.5÷1.25÷0.8=20.5÷(1.25×0.8)=20.5÷1=20.5④9.88×9+9.88=9.88×(9+1)=9.88×10=98.8 23.【解答】解:(1)12.6÷(1.02+3.18)=12.6÷4.2=3;(2)5.7×6.9+4.3×6.9=(5.7+4.3)×6.9=10×6.9=69;(3)(0.81+2.7)÷0.9=3.51÷0.9=3.9;(4)[(8.4﹣7.9)÷0.25]×1.2=[0.5÷0.25]×1.2=2×1.2=2.4. 24.【解答】解:(1)25×1.25×32 =25×1.25×8×4=(25×4)×(1.25×8)=100×10=1000(2)(+)×35=×35+×35=10+7=17(3)78×=(79﹣1)×=79×﹣=3﹣=2(4)÷+=÷= 25.【解答】解:(1)1.6×3.9×1.25=0.8×2×3.9×1.25=(0.8×1.25)×(2×3.9)=1×7.8=7.8(2)4.87×2.34+48.7×0.266=4.87×2.34+4.87×2.66=4.87×(2.34+2.66)=4.87×5=24.35(3)0.49×9.9 =0.49×(10﹣0.1)=0.49×10﹣0.49×0.1=4.9﹣0.049=4.851(4)0.05×0.7×20×1.7=(0.05×20)×(0.7×1.7)=1×1.19=1.19(5)2.5×3.2×12.5 =2.5×0.4×8×12.5 =(2.5×0.4)×(8×12.5)=1×100=100(6)3.95×7.6+3.95×3.4﹣3.95=3.95×(7.6+3.4﹣1)=3.95×10=39.5 26.【解答】解:(1)7.8×6.9+2.2×6.9=(7.8+2.2)×6.9=10×6.9=69(2)2.36×2.5×4=2.36×(2.5×4)=2.36×10=23.6(3)102×0.45=(100+2)×0.45=100×0.45+2×0.45=45+0.9=45.9(4)4.19×99+4.19=4.19×(99+1)=4.19×100=419(5)21.36÷0.8﹣12.9=26.7﹣12.9=13.8(6)3.2÷0.8×0.26=4×0.26=1.04 27.【解答】解:(1)6.33×101﹣6.33=6.33×(101﹣1)=6.33×100=633;(2)1.6×55.4﹣55.4×0.6=(1.6﹣0.6)×55.4=1×55.4=55.4;(3)17.68÷5.2+2.7×1.5=3.4+4.05=7.45;(4)(1.1﹣0.78)×(2.7﹣1.95)=0.32×0.75=0.24;(5)35.6﹣5×1.73=35.6﹣8.65=26.95;(6)15÷0.2÷2.5=15÷(0.2×2.5)=15÷0.5=30. 28.【解答】解:(1)2.5×1.37×0.4=2.5×0.4×1.37=1×1.37=1.37;(2)4.8×0.25×25=(4×4×0.3)×0.25×25=(4×0.25)×(4×25)×0.3=1×100×0.3=30;(3)0.89×4.8+0.89×5.2=0.89×(4.8+5.2)=0.89×10=8.9;(4)101×0.78×20=101×(0.78×20)=101×15.6=(100+1)×15.6=100×15.6+1×15.6=1560+15.6=1575.6;(5)8.8×1.25×15=(8×1.1)×1.25×15=(8×1.25)×(1.1×15)=10×16.5=165;(6)4.3×0.8×5=4.3×(0.8×5)=4.3×4=17.2. 29.【解答】解:(1)44.28÷0.9÷4.1=49.2÷4.1=12;(2)0.25×0.39×4=(0.25×4)×0.39=1×0.39=0.39;(3)7.6+7.6×99=7.6×(1+99)=7.6×100=760;(4)9.07﹣22.78÷3.4=9.07﹣6.7=2.37;(5)4.8×99+4.8=4.8×(99+1)=4.8×100=480;(6)6.3×10.1=6.3×(10+0.1)=6.3×10+6.3×0.1=63+0.63=63.63. 30.【解答】解:(1)5.8+3.8×0.25=5.8+0.95=6.75(2)1.7×(4.65﹣3.87)=1.7×0.78=1.326(3)1.25×4.3×0.8=1.25×0.8×4.3=1×4.3=4.3(4)4.5×102=4.5×(100+2)=4.5×100+4.5×2=450+9=459(5)0.54×101﹣0.54=0.54×(101﹣1)=0.54×100=54(6)3.4×2.5+6.6×2.5=(3.4+6.6)×2.5=10×2.5=25 31.【解答】解:①0.45×12×0.2=0.45×0.2×12=0.09×12=1.08 ②6.2×2.1﹣2.1=2.1×(6.2﹣1)=2.1×5.2=10.92③0.9×0.8×100=0.72×100=72④2.8﹣2.8×0.15 =2.8×(1﹣0.15)=2.8×0.85=2.38 ⑤2.8×1.43+0.57 =4.004+0.57=4.574⑥72×0.81+10.3=58.32+10.3=68.62⑦10﹣6.06+8.5=3.94+8.5=12. 44 ⑧6×0.25×1.8 =1.5×1.8=2.7⑨7.06×2.4﹣5.8 =16.944﹣5.8=11.144 32.【解答】解:(1)0.25×9.87×4 =0.25×4×9.87=1×9.87=9.87;(2)36.2×1.8+13.8×1.8 =(36.2+13.8)×1.8=50×1.8=90;(3)0.125×2.3×8=0.125×8×2.3=1×2.3=2.3;(4)0.73×102 =0.73×(100+2)=0.73×100+0.73×2=73+1.46=74.46;(5)(6.8+2.6)×5 =6.8×5+2.6×5=34+13=47;(6)0.23×98=0.23×(100﹣2)=0.23×100﹣0.23×2=23﹣0.46=22.54. 33.【解答】解:(1)12.5×32×2.5=12.5×4×8×2.5=(12.5×8)×(2.5×4)=100×10=1000;(2)6.8×9.9 =6.8×(10﹣0.1)=6.8×10﹣6.8×0.1=68﹣0.68=67.32;(3)7.2÷[1.8×(3.4﹣2.9)]=7.2÷[1.8×0.5]=7.2÷0.9=8. 34.【解答】解:(1)3.4×9+3.4=30.6+3.4=34;(2)6.4÷0.8﹣1.5×4=8﹣6=2;(3)3.78÷0.25÷4=3.78÷(0.25×4)=3.78÷1=3.78;(4)17÷[(1.2+0.5)×5]=17÷[1.7×5]=17÷8.5=2. 35.【解答】解:(1)2.5×1.25×8×0.4=(2.5×0.4)×(1.25×8)=1×10=10;(2)12.8×1.7+87.2×1.7=(12.8+87.2)×1.7=100×1.7=170;(3)100﹣4.35﹣5.65=100﹣(4.35+5.65)=100﹣10=90. 36.【解答】解:(1)4+7.6×15 =4+114=118;(2)26.08÷0.25÷4=26.08÷(0.25×4)=26.08÷1=26.08;(3)19.7+(80.5÷35×0.2)=19.7+(2.3×0.2)=19.7+0.46=20.16. 37.【解答】解:(1)1.25×2.25×0.8=1.25×0.8×2.25=1×2.25=2.25;(2)9.7×99+9.7=9.7×(99+1)=9.7×100=970;(3)4.8×7.8+78×0.52=4.8×7.8+7.8×5.2=(4.8+5.2)×7.8=10×7.8=78;(4)3.65×10.1=3.65×(10+0.1)=3.65×10+3.65×0.1=36.5+0.365=36.865. 38.【解答】解:①12.36﹣6.49﹣3.51=12.36﹣(6.49+3.51)=12.36﹣10=2.36;②8.5×3.8+8.5×6.2=8.5×(3.8+6.2)=8.5×10=85;③17.3×0.25×8=17.3×(0.25×8)=17.3×2=34.6;④15.32﹣1.8×5﹣3.46=15.32﹣9﹣3.46=6.32﹣3.46=2.86;⑤199×2.6=(200﹣1)×2.6=200×2.6﹣1×2.6=520﹣2.6=517.4;⑥3.6÷[(1.3+0.6)×5]=3.6÷[1.9×5]=3.6÷9.5=. 39.【解答】解:(1)8.5+6.85﹣6.35=8.5+(6.85﹣6.35)=8.5+0.5=9;(2)3.9+0.1﹣3.9+0.1 =(3.9﹣3.9)+(0.1+0.1)=0+0.2=0.2;(3)12.6﹣(3.75+5.08)=12.6﹣8.83=3.77. 40.【解答】解:(1)6.09﹣9.13÷8.3=6.09﹣1.1=4.99(2)3.84×9.6+0.96×61.6 =(3.84+6.16)×9.6=10×9.6=96(3)4.86×99=4.86×(100﹣1)=4.86×100﹣4.86=486﹣4.86=481.14(4)5.68×4+4.32÷0.25=5.68×4+4.32×4=(5.68+4.32)×4=10×4=40(5)6.4×4.5+3.6×4.5=(6.4+3.6)×4.5=10×4.5=45 41.【解答】解:①10.5+61×18=10.5+1098=1108.5 ②(3.14+12.6)÷8=15.74÷8=1.9675③4.5÷(15÷3)=4.5÷5=0.9④75+448÷4×19=75+112×19=75+2128=2203 42.【解答】解:(1)(18.5×3.8+3.8×2.5)÷0.19 =3.8×(18.5+2.5)÷0.19 =3.8×21÷0.19=3.8÷0.19×21=200×21=4200(2)[32﹣(7.25+0.75×8)]÷50=[32﹣(7.25+6)]÷50=[32﹣13.25]÷50=18.75÷50=0.375 43.【解答】解:①25.32﹣(3.4﹣1.2)=25.32﹣2.2=23.12②12﹣0.62﹣4.38=12﹣(0.62+4.38)=12﹣5=7 44.【解答】解:(1)5.12+2.54+4.88=5.12+4.88+2.54=10+2.54=12.54;(2)12.5×17.8×0.8=12.5×0.8×17.8=10×17.8=178;(3)0.24×0.48×4=0.1152×4=0.4608;(4)9.9×2.5=(10﹣0.1)×2.5=10×2.5﹣0.1×2.5=25﹣0.25=24.75;(5)9.4×5.8+10.6×5.8=(9.4+10.6)×5.8=20×5.8=116;(6)0.66×101=0.66×(100+1)=0.66×100+0.66×1=66+0.66=66.66;(7)4.8×0.25=(1.2×4)×0.25=1.2×(4×0.25)=1.2×1=1.2;(8)2.33×0.5×4 =2.33×(0.5×4)=2.33×2=4.66;(9)1.3×2.5+0.7×2.5=(1.3+0.7)×2.5=2×2.5=5;(10)1.26×0.6+1.26×0.4=1.26×(0.6+0.4)=1.26×1=1.26;(11)102×0.55=(100+2)×0.55=100×0.55+2×0.55=55+1.1=56.1;(12)0.034×0.5×0.2=0.034×(0.5×0.2)=0.034×0.1=0.0034. 45.【解答】解:(1)13.38+0.98=13.38+(1﹣0.02)=13.38+1﹣0.02=14.38﹣0.02=14.36;(2)7.02﹣2.98 =7.02﹣(3﹣0.02)=7.02﹣3+0.02 =4.02+0.02=4.04;(3)6.57﹣(0.68﹣0.39+0.32)=6.57﹣(0.68+0.32﹣0.39)=6.57﹣(1﹣0.39)=6.57﹣0.61=5.96;(4)13.8÷(1.38×0.2)=13.8÷1.38÷0.2=10÷0.2=50;(5)30.7﹣0.12×2﹣0.76=30.7﹣0.24﹣0.76=30.7﹣(0.24+0.76)=30.7﹣1=29.7;(6)7.8×1.01=7.8×(1+0.01)=7.8×1+7.8×0.01=7.8+0.078=7.878;(7)18.4﹣6.5+1.6+3.5 =(18.4+1.6)﹣(6.5﹣3.5)=20﹣3=17;(8)7.8÷0.6+7.8÷0.4=13+19.5=32.5;(9)12.13+7.5﹣1.13+2.85=(12.13﹣1.13)+(7.5+2.85)=11﹣10.35=0.65;(10)0.125×8.8=0.125×(8+0.8)=0.125×8+0.125×0.8=1+0.1=1.1;(11)9.4×3.2+6×0.32=9.4×3.2+0.6×3.2=(9.4+0.6)×3.2=10×3.2=32;(12)9.6×3.6+7.2×0.2=9.6×3.6+3.6×2×0.2=9.6×3.6+3.6×0.4=(9.6+0.4)×3.6=10×3.6=36. 46.【解答】解:(1)96÷(100×0.48)=96÷48=2;(2)3.6÷(1.2+0.5)×6=3.6÷1.7×6=×6=;(3)(967﹣31)÷(17+48)=936÷65=14.4;(4)72×10.1+27×10.1=(72+27)×10.1=99×10.1=99×(10+0.1)=99×10+99×0.1=990+9.9=999.9. 47.【解答】解:(1)3.4×7.8÷3.9=26.52÷3.9=6.8;(2)54÷(3.94+6.86)=54÷10.8=5. 48.【解答】解:①0.486+0.01+3.99 =0.486+(0.01+3.99)=0.486+4=4.486 ②17.5×2.3﹣7.5×2.3 =2.3×(17.5﹣7.5)=2.3×10=23 ③1.25×11×4×0.8=(1.25×0.8)×(11×4)=1×44=44④4.8×39+61×4.8=4.8×(39+61)=4.8×100=480⑤45.55﹣(6.82+15.55)=45.55﹣6.82﹣15.55=45.55﹣15.55﹣6.82=30﹣6.82=23.18⑥3.2×99+3.2=3.2×(99+1)=3.2×100=320⑦2.5×56+4.5×56 =56×(2.5+4.5)=56×7=392⑧(31.6﹣11.7)÷2.5÷4 =19.9÷(2.5×4)=19.9÷10=1.99⑨3.6×0.9+3.6×0.1=3.6×(0.9+0.1)=3.6×1=3.6 49.【解答】解:(1)7.5﹣2.4÷0.8×2.5 =7.5﹣3×2.5=7.5﹣7.5=0;(2)12.5×17+83×12.5=12.5×(17+83)=12.5×100=1250;(3)399×2.5=(400﹣1)×2.5=400×2.5﹣2.5=1000﹣2.5=997.25;(4)25÷(2.5÷0.4)=25÷2.5×0.4=10×0.4=4;(5)3.25×67+5.75×67+67 =(3.25+5.75+1)×67=10×67=670;(6)230÷2.5×7.5=92×7.5=690;(7)6.3+0.84+3.7+8.16=(6.3+3.7)+(0.84+8.16)=10+9=19;(8)100﹣(2.72+10.8)÷0.2=100﹣13.52÷0.2=100﹣67.6=32.4. 50.【解答】解:(1)0.25×3.25×4=0.25×4×3.25=1×3.25=3.25(2)6.72+3.2÷2.5=6.72+1.28=8(3)21.36÷0.4﹣23.4=53.4﹣23.4=30(4)0.8×4.5+1.2×4.5=(0.8+1.2)×4.5=2×4.5=9 。

小数乘除法简便计算

小数乘除法简便计算

小数乘除法简便计算小数乘法的简便计算方法:1.保留位数法:将两个小数的位数之和作为结果的小数位数,按照小数点对齐相乘,然后将小数点向左移位,使得结果的小数位数等于位数之和。

例如:0.25×1.2=0.300.025×0.16=0.0042.科学记数法法:将两个小数转化为科学记数法形式,然后按照整数乘法的步骤计算,最后将结果恢复为小数形式。

例如:0.25×1.2=(2.5×10^(-1))×(1.2×10^(0))=3×10^(-1)=0.30.025×0.16=(2.5×10^(-2))×(1.6×10^(-1))=4×10^(-3)=0.004小数除法的简便计算方法:1.保留位数法:将两个小数的位数之和作为商的小数位数,按照小数点对齐相除,然后将小数点向右移位,使得商的小数位数等于位数之和。

例如:2.4÷0.6=40.25÷0.08=3.1252.科学记数法法:将两个小数转化为科学记数法形式,然后按照整数除法的步骤计算,最后将结果恢复为小数形式。

例如:2.4÷0.6=(2.4×10^(0))÷(0.6×10^(0))=4×10^(0)=40.25÷0.08=(2.5×10^(-1))÷(8×10^(-2))=3.125×10^(0)=3.125除了以上的简便计算方法,还可以结合竖式计算法进行小数乘除法的求解。

在竖式计算法中,首先进行小数的整数部分的乘除运算,然后再进行小数部分的乘除运算。

这样可以逐位进行计算,减少计算错误的可能性。

总的来说,简便计算方法能够帮助我们更快地求解小数的乘除法,提高计算效率。

但需要注意的是,在使用简便计算方法时,需要根据具体情况选择合适的方法,并且在最终的结果中恢复小数的形式。

小数的除法知识点总结和计算题(附答案)

小数的除法知识点总结和计算题(附答案)

小数除法知识点及同步练习小数除法法则:利用商不变性质,将除数变成整数,被除数扩大相同的倍数,再根据除数是整数的方法进行计算,除到哪位商哪位,被除数的小数点和商的小数点对齐。

求商的近似值:根据要求除到所需保留位数的后一位即可。

能运用商不变的性质进行小数除法的简算,能进行小数除法的估算。

循环小数:①能正确的识别循环小数、有限小数②能根据余数的特点正确的找到循环节,能用简便记法表示循环小数③能够进行循环小数和有限小数的比大小。

会求循环小数的近似值④循环小数相关概念一个小数,从小数部分的某一位起,一个数字或者几个数字依次不断地重复出现,这样的小数叫做循环小数。

循环节:循环小数中重复出现的数字。

循环小数的一般写法:写两个循环节,点上省略号。

简便写法:写一个循环节,在首位和末位点上循环点。

被除数、除数、商的变化规律:被除数和除数同时扩大(缩小)相同的倍数,商不变。

除数不变,被除数扩大(缩小)多少倍,商扩大(缩小)多少倍。

被除数不变,除数扩大(缩小)多少倍,商缩小(扩大)多少倍。

小数除法中的比大小:当除数大于1时,商小于被除数。

(被除数≠0)当除数小于1时,商大于被除数。

(被除数≠0)当除数等于1时,商等于被除数。

经典示例:1.列竖式计算。

(带*的验算,除不尽的商保留两位小数)(1)*205.8÷14=(2)0.13÷0.17≈(3)27.9÷4.5=(4)9.76÷2.2≈(1)205.8÷14=14.7验算:14.7×14=205.8(2)0.13÷0.17≈0.76(3)27.9÷4.5=6.2(4)9.76÷2.2≈4.442.列竖式计算。

(带△的需验算,带※的商保留两位小数,商是循环小数的要简写)(1)△4.872÷2.4 (2)△11.7÷0.18 (3)※5.63÷7.8 (4)4÷15(1)4.872÷2.4=2.03 验算:(2)11.7÷0.18=65 验算:(3)5.63÷7.8≈0.72(4)4÷15=0.26.3.列竖式计算。

小数除法脱式运算+简算300道(含答案)

小数除法脱式运算+简算300道(含答案)

小数除法脱式运算+简算300道一.计算题(共50小题)1.用递等式进行计算,能简便的要简便简便计算.7.29×4.6+46×1.271 (28.7﹣18.6÷3.1)×0.8 16﹣5.32﹣4.68 3.7×0.125+6.3÷8 40.8+14.7÷(14.6﹣12.5)0.72+9.6÷3.22.用简便方法计算.3.7×4.5﹣4.4×3.70.25×0.25×4 3.84﹣1.9+0.16﹣1.19﹣7÷2.5×0.4 5.5×[0.672÷(2+2.2)]3.用递等式计算,能简算的要简算.28.7÷7×4.59.6÷(15.4﹣12.2)4.6×1.2+2.8×4.693÷3.1÷0.34.计算下列各题(能用简便算法的要用简便算法).(4.15+0.65)×0.9 9.06×14.7+5.3×9.06(2.3+1.05÷2.1)×2.5 9.18÷[(5.9﹣2.3)×0.25].5.选择合理的方法进行计算,并写出计算主要过程.12.5×0.5×8 17.5÷(5.7﹣3.2)48.77﹣32.76÷8.410.25÷2.5÷0.4 18.1﹣2.8×4.6 3.01×101﹣30.1×0.1.6.脱式计算,能简算的要简算.4.8÷2.04÷2.4 1.1÷(22÷5)25÷40×0.472+0.9÷0.125 17.37÷0.45﹣3.86÷0.1 9.07﹣22.78÷3.4+3.7.7.用递等式计算,能简算的要简算.10.01×101﹣10.01 0.11×1.8+8.2×0.1126×20.2﹣8.4﹣1.8 12.05÷1.25÷0.8.8.递等式计算(能简算的要简算)6.5×99 4.65﹣2.55﹣1.45 2.2×0.25+2.8×0.25 0.25×6.82×4.9.计算下面各题,能简算的要简算.102×4.5 8×(20﹣1.25)8.3+8.3×99 (1.25+12.5+125)×8.10.计算(能简算要简算)2.64+8.67+7.36+11.33 2.74×9.5+0.5×2.7(2400﹣480×2.5)÷1.616.8×10.1 1.25×88 6.87×[40÷(3.49﹣3.09)].11.脱式计算(能简简的要简算)2.8+0.2﹣2.8+0.2 37÷12.5÷0.8 1.25×(10+0.8)10.8﹣3.8×0.4÷0.76 0.36÷[(6.1﹣4.6)×0.8].12.计算下面各题,能简算的要简算.4.05÷0.9+5.5 3.67×10.1﹣3.67×0.199×0.73+0.73 3.3+6.7×3.5.13.怎样简便怎样算3.7÷2.5÷0.40.25×1.25×329.83×1.5+0.617×15.14.计算下面各题.(能简算的要简算)12.13+7.5﹣12.13 7.69﹣(3.7+2.69)7.8×1.019.4×3.2+6×0.32 12.5×3.2 13.8÷(1.38×2)15.下面各题,怎样简便就怎样算432.5÷25÷0.4 1.25×3.2×2.5 0.81×99+0.815.9×10.1 100﹣52.8﹣47.2(4﹣0.4)×0.25.16.计算下面各题,能简算的要简算.0.75×18÷0.15 9.3÷0.125÷8 1.78×99+1.784.7×4.28+5.3×4.28 2.3×10.2 21.36÷0.2﹣25.9.17.怎样简便就怎样计算28.4×99+28.4 3.6×2010.94×2.5﹣0.454×0.8×12.5×2.517.5÷0.25×17+1315.58÷8.2﹣0.72.18.计算,能简算的要简算.1.25×2.5×0.8×43=10÷0.2÷2.5=8.4÷0.21÷0.5=64×4.5+3.6×45= 1.25×3.2×0.8=14.5×102=19.脱式计算,能简算的要简算.0.34×101 8.8×1.25 2.94×6.3+3.7×2.9421.9﹣9.28﹣10.72 2.7+(11.2﹣2.7)×0.4 1.5×[0.02÷(2.1﹣2.09)].20.计算下面各题.(能简算的要简算)10.7﹣22.78÷3.4 5.5×17.3+6.7×5.5 3.76÷0.4÷2.5 0.25×12.5×3.2.21.递等式计算,能简便计算的要简便计算.4.6×25 3.75÷12.5÷0.8 2.5+7.5÷4(3.2﹣1.4)÷0.18﹣1.87.9×7.1+2.9×7.9(30.2﹣4.6×5)÷0.12.22.下面各题,怎样简便就怎样计算.0.75×0.5×0.8 5.6×15.7+9.3×5.6 50.4×1.9﹣1.8.23.计算下面各题,注意运用简便方法.2.4﹣0.2÷5×60 0.25×6.8×405.52﹣0.55﹣0.45 0.49×7.2﹣7.2×0.39.24.计算,能简算的要写出简算过程.4×0.8×2.5×12.5 2.25×4.8+77.5×0.48.25.计算下面各题,能简算的要简算.13.73+6.27÷0.318÷0.4÷2.5 0.75×99+0.752.85×5.35+2.85×4.65 1.5×0.4÷1.5×0.4.26.怎样简便就怎样计算28.4×99+28.4 3.6×201 0.94×2.5﹣0.454×0.8×12.5×2.5 17.5÷0.25×17+13 1.25×8.08.27.下面各题,怎样算简便就怎样算.2.45﹣(1.45+0.89) 1.25×1.7×0.8 5.3×0.82﹣0.82×0.33.6÷[12×(0.53﹣0.45)].28.计算下面各题,能简算的要简算.125×32×2.5 2.6×(3.4+1.6) 6.7×5.5+5.5×3.3.36×999.07﹣2.2﹣7.817.6÷4÷2.529.计算下面各题,能简算的要简算.2.5×0.27×4 0.63×101 0.78+0.22÷53.7×12.5+4.3×12.5 (0.36+5.4)÷0.6 4.5÷0.25÷1.6.30.脱式计算(能简便的用简便计算).1.6×(2.25+10.5÷1.5)74×57+43×740.6÷[(6.1﹣4.6)×0.8]101×92﹣92125×64 46.2×0.56+5.37×5.6+1×0.05631.脱式计算(能简算的就简算)1.5×102 1.25×213×0.8 72×0.81﹢10.41.25×5.6 6.05÷0.5+10.75 29.6÷0.8﹣1.2×5.32.脱式计算下列各题,能简算的要简算.2.69×99+2.69 1.25×2.3×0.83.17×5.6+4.4×3.1738÷0.25÷0.4 6.5÷0.125 0.225÷0.25×433.脱式计算(能简算的要简算).17.54+28.35+3.46+1.55 32.36﹣13.43﹣(7.57+1.36)7.2×2.745÷0.363.85×5.6+5.4×3.85﹣3.85 (3.2+0.128)÷0.8 (13.3﹣8.8)×3.2÷0.36.34.脱式计算(能简算的要简算)0.75×4×0.25×4 6.3×10.115.58÷8.2﹣0.72 4.536÷0.8÷14.35.脱式计算,能简算的要简算.7.5×2+1.25÷0.598×7.580÷0.25+0.75 19×3.8+3.8 1.25×3.4×0.8 5.12÷0.4÷2.536.计算,能简算的要简算55.04+12.8﹣3.30.25×32×0.1257.8×75+75×0.2.37.用你喜欢的方法计算.0.21×14÷0.50.25×13×4 1.25×9.7﹣1.25×1.716.5÷[(5.2+4.8)×1.5](8.92﹣0.45)÷(2.5+4.5)38.下面各题怎样算简便就怎样算.6.8×0.46+0.54 5.4×2.3+5.4×7.70.25×32×12.5 75÷1.25÷8.39.用递等式计算,(有★用简算)7.8﹣7.2+0.9 0.38+0.26+3.4 (125﹣45)×313+[(41+22)÷9]★6.7+2.5+3.3★13×25×4.40.脱式计算,能简算的要简算12.8+2.04×9.50.15×1999+0.150.76×6.5﹣0.76×5.578÷0.25÷0.4.41.计算下面各题,怎样简便就怎样计算.4.05÷0.5+10.75 6.8×2.7+2.7×3.2 6.8×0.75÷0.570.3﹣17.48÷7.6 8.5×1.2÷3.4 13.75÷0.125﹣2.7.42.计算下面各题,能用简便方法计算的要用简便方法.0.75×18÷0.15 6.15÷0.125÷0.8 4.55÷0.28﹣0.471.7×2.5×0.08 1.89×11﹣1.893.6×0.35+6.4×0.3543.计算下面各题,能简算的要简算.3.4+6.6÷0.3 25×1.25×0.04×0.899×0.73+7.3×0.1 96.5÷1.25÷0.8.44.脱式计算(能简算的用简算方法)82.4﹣12.4×5 18.5﹣3.21﹣4.79 8.4+3.8+1.6+6.20.25×17.3×0.4 7.2×(10+0.1) 3.54×0.29﹣0.29×2.5445.计算下列各题,怎么简便就怎么算.0.125×32 8.8÷0.25÷4 56.5×99+56.50.78×1019.9﹣2.07÷2.312.75÷[14.6﹣(1.3+8.2)].46.计算,能简算的要简算.60.8﹣36÷3.6 12.5×7.2×0.899×78.5+78.5 24.6﹣8.9﹣1.10.9+9.9+99.9+999.9 695÷25÷4.47.脱式计算(能简算的要简算)5.8+6.3÷9×0.5 1.25×0.8÷1.25×0.8 1.92÷0.12﹣2.72.65×1.7+1.35×1.7﹣1.7138÷0.25÷4 1.25×2.5×3.248.你能想出简便方法来计算下面各题吗?25×5+74×5+5 6.74+12.62+24.38+3.2687﹣2.123﹣0.877 30.65﹣(7.65+5.4)(40+8)×125 32×38+32×62.49.脱式计算.(能简算的要简算)65×102 8.23﹣(2.67+3.23)32×16+14×32 8.46+7.26+1.51+2.84 27×[(263+37)÷50]125×32×25.50.递等式计算(能简算的要简算)5.6×0.25 0.32×0.25×12.56.4÷(0.3×2+0.2)201×6.5﹣6.5 102×4.5 2.2×0.25+2.8×0.25.小数除法脱式运算+简算300道参考答案与试题解析一.计算题(共50小题)1.【解答】解:①7.29×4.6+46×1.271 =7.29×4.6+4.6×12.71=(7.29+12.71)×4.6=20×4.6=92;②(28.7﹣18.6÷3.1)×0.8 =(28.7﹣6)×0.8=22.7×0.8=18.16;③16﹣5.32﹣4.68=16﹣(5.32+4.68)=16﹣10=6;④3.7×0.125+6.3÷8 =3.7×+6.3×=(3.7+6.3)×=10×=;⑤40.8+14.7÷(14.6﹣12.5)=40.8+14.7÷2.1=40.8+7=47.8;⑥0.72+9.6÷3.2=0.72+3=3.72.2.【解答】解:(1)3.7×4.5﹣4.4×3.7=3.7×(4.5﹣4.4)=3.7×0.1=0.37;(2)0.25×0.25×4=0.25×(0.25×4)=0.25×1=0.25;(3)3.84﹣1.9+0.16﹣1.1=(3.84+0.16)﹣(1.9+1.1)=4﹣3=1;(4)9﹣7÷2.5×0.4=9﹣2.8×0.4=9﹣1.12=7.88;(5)5.5×[0.672÷(2+2.2)]=5.5×[0.672÷4.2]=5.5×0.16=0.88.3.【解答】解:(1)28.7÷7×4.5=4.1×4.5=18.45(2)9.6÷(15.4﹣12.2)=9.6÷3.2=3(3)4.6×1.2+2.8×4.6=4.6×(1.2+2.8)=4.6×4=18.4(4)93÷3.1÷0.3=30÷0.3=1004.【解答】解:(1)(4.15+0.65)×0.9=4.8×0.9=4.32;(2)9.06×14.7+5.3×9.06=9.06×(14.7+5.3)=9.06×20=181.2;(3)(2.3+1.05÷2.1)×2.5=(2.3+0.5)×2.5=2.8×2.5=7;(4)9.18÷[(5.9﹣2.3)×0.25]=9.18÷[3.6×0.25]=9.18÷0.9=10.2.5.【解答】解:(1)12.5×0.5×8=12.5×8×0.5=100×0.5=50;(2)17.5÷(5.7﹣3.2)=17.5÷2.5=7;(3)48.77﹣32.76÷8.4=48.77﹣3.9=44.87;(4)10.25÷2.5÷0.4=10.25÷(2.5×0.4)=10.25÷1=10.25;(5)18.1﹣2.8×4.6=18.1﹣12.88=5.22;(6)3.01×101﹣30.1×0.1=3.01×(101﹣1)=30.1×100=30100.6.【解答】解:(1)4.8÷2.04÷2.4=4.8÷2.4÷2.04=2÷2.04=(2)1.1÷(22÷5)=1.1÷22×5=0.05×5=0.25(3)25÷40×0.4=25×0.4÷40=10÷40=0.25(4)72+0.9÷0.125=72+7.2=79.2(5)17.37÷0.45﹣3.86÷0.1=38.6﹣38.6=0(6)9.07﹣22.78÷3.4+3.7=9.07﹣6.7+3.7=2.37+3.7=6.077.【解答】解:(1)10.01×101﹣10.01=10.01×(101﹣1)=10.01×100=1001(2)0.11×1.8+8.2×0.11=0.11×(1.8+8.2)=0.11×10=1.1(3)26×20.2﹣8.4﹣1.8=525.2﹣(8.4+1.8)=525.2﹣10.2=515(4)12.05÷1.25÷0.8=12.05÷(1.25×0.8)=12.05÷1=12.058.【解答】解:①6.5×99=6.5×(100﹣1)=6.5×100﹣6.5=650﹣6.5=643.5②4.65﹣2.55﹣1.45=4.65﹣(2.55+1.45)=4.65﹣4=0.65③2.2×0.25+2.8×0.25=(2.2+2.8)×0.25=5×0.25=1.25④0.25×6.82×4=(0.25×4)×6.82=1×6.82=6.829.【解答】解:①102×4.5=(100+2)×4.5=100×4.5+2×4.5=450+9=459②8×(20﹣1.25)=8×20﹣8×1.25=160﹣10=150③8.3+8.3×99 =8.3×(1+99)=8.3×100=830④(1.25+12.5+125)×8=1.25×8+12.5×8+125×8=10+100+1000=110+1000=111010.【解答】解:①2.64+8.67+7.36+11.33=(2.64+7.36)+(8.67+11.33)=10+20=30②2.74×9.5+0.5×2.7=26.03+1.35=27.38③(2400﹣480×2.5)÷1.6=(2400﹣1200)÷1.6=1200÷1.6=750④16.8×10.1=16.8×(10+0.1)=16.8×10+16.8×0.1=168+1.68=169.68⑤1.25×88=1.25×(80+8)=1.25×80+1.25×8=100+10=110⑥6.87×[40÷(3.49﹣3.09)]=6.87×[40÷0.4]=6.87×100=68711.【解答】解:(1)2.8+0.2﹣2.8+0.2=(2.8﹣2.8)+(0.2+0.2)=0+0.4=0.4(2)37÷12.5÷0.8=37÷(12.5×0.8)=37÷10=3.7(3)1.25×(10+0.8)=1.25×10+1.25×0.8=12.5+1=13.5(4)10.8﹣3.8×0.4÷0.76=10.8﹣1.52÷0.76=10.8﹣2=8.8(5)0.36÷[(6.1﹣4.6)×0.8]=0.36÷[1.5×0.8]=0.36÷1.2=0.3 12.【解答】解:(1)4.05÷0.9+5.5=4.5+5.5=10(2)3.67×10.1﹣3.67×0.1=3.67×(10.1﹣0.1)=3.67×10=36.7(3)99×0.73+0.73=(99+1)×0.73=100×0.73=73(4)3.3+6.7×3.5=3.3+23.45=26.7513.【解答】解:①3.7÷2.5÷0.4=3.7÷(2.5×0.4)=3.7÷1=3.7②0.25×1.25×32=0.25×1.25×(4×8)=(0.25×4)×(1.25×8)=1×10=10③9.83×1.5+0.617×15=9.83×1.5+6.17×1.5=1.5×(9.83+6.17)=1.5×16=2414.【解答】解:①12.13+7.5﹣12.13=12.13﹣12.13+7.5=0+7.5=7.5 ②7.69﹣(3.7+2.69)=7.69﹣3.7﹣2.69=7.69﹣2.69﹣3.7=5﹣3.7=1.3③7.8×1.01=7.8×(1+0.01)=7.8×1+7.8×0.01=7.8+0.078=7.878④9.4×3.2+6×0.32=9.4×3.2+0.6×3.2=3.2×(9.4+0.6)=3.2×10=32 ⑤12.5×3.2=12.5×(8×0.4)=12.5×8×0.4=100×0.4=40 ⑥13.8÷(1.38×2)=13.8÷1.38÷2=10÷2=515.【解答】解:①432.5÷25÷0.4=432.5÷(25×0.4)=432.5÷10=43.25②1.25×3.2×2.5=1.25×(8×0.4)×2.5=(1.25×8)×(0.4×2.5)=10×1=10③0.81×99+0.81=0.81×(99+1)=0.81×100=81④5.9×10.1 =5.9×(10+0.1)=5.9×10+5.9×0.1=59+0.59=59.59⑤100﹣52.8﹣47.2=100﹣(52.8+47.2)=100﹣100=0⑥(4﹣0.4)×0.25=4×0.25﹣0.4×0.25=1﹣0.1=0.916.【解答】解:(1)0.75×18÷0.15 =0.75÷0.15×18=5×18=90;(2)9.3÷0.125÷8 =9.3÷(0.125×8)=9.3÷1=9.3;(3)1.78×99+1.78=1.78×(99+1)=1.78×100=178;(4)4.7×4.28+5.3×4.28 =(4.7+5.3)×4.28=10×4.28=42.8;(5)2.3×10.2 =2.3×(10+0.2)=2.3×10+2.3×0.2=23+0.46=23.46;(6)21.36÷0.2﹣25.9=106.8﹣25.9=80.9.17.【解答】解:(1)28.4×99+28.4=28.4×(99+1)=28.4×100=2840(2)3.6×201=3.6×(200+1)=3.6×200+3.6×1=720+3.6=723.6(3)0.94×2.5﹣0.45=2.35﹣0.45=1.9(4)4×0.8×12.5×2.5=(4×2.5)×(0.8×12.5)=10×10=100(5)17.5÷0.25×17+13=70×17+13=1190+13=1203(6)15.58÷8.2﹣0.72=1.9﹣0.72=1.1818.【解答】解:(1)1.25×2.5×0.8×43=1.25×0.8×2.5×43=1×2.5×43=107.5;(2)10÷0.2÷2.5=10÷(0.2×2.5)=10÷0.5=20;(3)8.4÷0.21÷0.5=40÷0.5=80;(4)64×4.5+3.6×45=64×4.5+36×4.5=(64+36)×4.5=100×4.5=450;(5)1.25×3.2×0.8=1.25×0.8×3.2=1×3.2=3.2;(6)14.5×102=14.5×(100+2)=14.5×100+14.5×2=1450+29=1479.19.【解答】解:(1)0.34×101=0.34×(100+1)=0.34×100+0.34×1=34+0.34=34.34;(2)8.8×1.25=(1.1×8)×1.25=1.1×(8×1.25)=1.1×10=11;(3)2.94×6.3+3.7×2.94=2.94×(6.3+3.7)=2.94×10=29.4;(4)21.9﹣9.28﹣10.72=21.9﹣(9.28+10.72)=21.9﹣20=1.9;(5)2.7+(11.2﹣2.7)×0.4=2.7+8.5×0.4=2.7+3.4=6.1;(6)1.5×[0.02÷(2.1﹣2.09)]=1.5×[0.02÷0.01]=1.5×2=3.20.【解答】解:①10.7﹣22.78÷3.4 =10.7﹣6.7=4②5.5×17.3+6.7×5.5=5.5×(17.3+6.7)=5.5×24=132③3.76÷0.4÷2.5=3.76÷(0.4×2.5)=3.76÷1=3.76 ④0.25×12.5×3.2=0.25×12.5×(4×0.8)=(0.25×4)×(12.5×0.8)=1×10=1021.【解答】解:(1)4.6×25=(4+0.6)×25=4×25+0.6×25=100+15=115;(2)3.75÷12.5÷0.8=3.75÷(12.5÷0.8)=3.75÷10=0.375;(3)2.5+7.5÷4=2.5+1.875=4.375;(4)(3.2﹣1.4)÷0.18﹣1.8=1.8÷0.18﹣1.8=10﹣1.8=8.2;(5)7.9×7.1+2.9×7.9=7.9×(7.1+2.9)=7.9×10=79;(6)(30.2﹣4.6×5)÷0.12=(30.2﹣23)÷0.12=7.2÷0.12=60.22.【解答】解:(1)0.75×0.5×0.8=0.75×(0.5×0.8)=0.75×0.4=0.3;(2)5.6×15.7+9.3×5.6=5.6×(15.7+9.3)=5.6×25=14×0.4×25=14×(0.4×25)=14×10=140;(3)50.4×1.9﹣1.8=95.76﹣1.8=93.96.23.【解答】解:①2.4﹣0.2÷5×60=2.4﹣0.04×60=2.4﹣2.4=0②0.25×6.8×40=(0.25×40)×6.8=10×6.8=68③5.52﹣0.55﹣0.45=5.52﹣(0.55+0.45)=5.52﹣1=4.52④0.49×7.2﹣7.2×0.39=7.2×(0.49﹣0.39)=7.2×0.1=0.7224.【解答】解:(1)4×0.8×2.5×12.5=(4×2.5)×(0.8×12.5)=10×10=100(2)×14+87×﹣=×(14+87﹣1)=×100=80(3)(+)×42 =×42+×42=35+12=47(4)2.25×4.8+77.5×0.48=2.25×4.8+7.75×4.8=(2.25+7.75)×4.8=10×4.8=48 25.【解答】解:(1)13.73+6.27÷0.3=13.73+20.9=34.63;(2)18÷0.4÷2.5=18÷(0.4×2.5)=18÷1=18;(3)0.75×99+0.75=0.75×(99+1)=0.75×100=75;(4)2.85×5.35+2.85×4.65=2.85×(5.35+4.65)=2.85×10=28.5;(5)1.5×0.4÷1.5×0.4=1.5÷1.5×0.4×0.4=1×0.4×0.4=0.4×0.4=0.16.26.【解答】解:(1)28.4×99+28.4=28.4×(99+1)=28.4×100=2840;(2)3.6×201=3.6×(200+1)=3.6×200+3.6×1=720+3.6=723.6;(3)0.94×2.5﹣0.45=2.35﹣0.45=1.9;(4)4×0.8×12.5×2.5=(4×2.5)×(0.8×12.5)=10×10=100;(5)17.5÷0.25×17+13=70×17+13=1190+13=1203;(6)1.25×8.08=1.25×(8+0.08)=1.25×8+1.25×0.08=10+0.1=10.1.27.【解答】解:①2.45﹣(1.45+0.89)=2.45﹣1.45﹣0.89=1﹣0.89=0.11②1.25×1.7×0.8=1.25×0.8×1.7=1×1.7=1.7③5.3×0.82﹣0.82×0.3=0.82×(5.3﹣0.3)=0.82×5=4.1 ④3.6÷[12×(0.53﹣0.45)]3.6÷12÷(0.53﹣0.45)=0.3÷0.08=3.7528.【解答】解:(1)125×32×2.5=125×(4×8)×2.5=(125×8)×(4×2.5)=1000×10=10000;(2)2.6×(3.4+1.6)=2.6×5=13;(3)6.7×5.5+5.5×3.3=(6.7+3.3)×5.5=10×5.5=55;(4)36×99=36×(100﹣1)=36×100﹣36×1=3600﹣36=3564;(5)9.07﹣2.2﹣7.8=9.07﹣(2.2+7.8)=9.07﹣10=﹣0.93;(6)17.6÷4÷2.5=17.6÷(4×2.5)=17.6÷10=1.76.29.【解答】解:(1)2.5×0.27×4=2.5×4×0.27=10×0.27=2.7;(2)0.63×101=0.36×(100+1)=0.36×100+0.36×1=36+0.36=36.36;(3)0.78+0.22÷5=0.78+0.044=0.824;(4)3.7×12.5+4.3×12.5=(3.7+4.3)×12.5=8×12.5=100;(5)(0.36+5.4)÷0.6=5.76÷0.6=9.6;(6)4.5÷0.25÷1.6=4.5÷(0.25×1.6)=4.5÷0.4=11.25.30.【解答】解:(1)1.6×(2.25+10.5÷1.5)=1.6×(2.25+7)=1.6×9.25=14.8;(2)74×57+43×74=74×(57+43)=74×100=7400;(3)0.6÷[(6.1﹣4.6)×0.8]=0.6÷[1.5×0.8]=0.6÷1.2=0.5;(4)101×92﹣92=(101﹣1)×92=100×92=9200;(5)125×64 =125×8×8=1000×8=8000;(6)46.2×0.56+5.37×5.6+1×0.056=4.62×5.6+5.37×5.6+0.01×5.6=(4.62+5.37+0.01)×5.6=10×5.6=56.31.【解答】解:①1.5×102 =1.5×(100+2)=1.5×100+1.5×2=150+3=153②1.25×213×0.8=1.25×0.8×213=1×213=213 ③72×0.81﹢10.4=58.32+10.4=68.72④1.25×5.6 =1.25×(8×0.7)=1.25×8×0.7=10×0.7=7⑤6.05÷0.5+10.75 =12.1+10.75=22.85⑥29.6÷0.8﹣1.2×5=37﹣6=31 32.【解答】解:(1)2.69×99+2.69=2.69×(99+1)=2.69×100=269(2)1.25×2.3×0.8=1.25×0.8×2.3=1×2.3=2.3(3)3.17×5.6+4.4×3.17=3.17×(5.6+4.4)=3.17×10=31.7(4)38÷0.25÷0.4=38÷(0.25×0.4)=38÷0.1=380(5)6.5÷0.125=6.5÷=6.5×8=52(6)0.225÷0.25×4=0.9×4=3.633.【解答】解:①17.54+28.35+3.46+1.55=17.54+3.46+(28.35+1.55)=21+29.9=50.9 ②32.36﹣13.43﹣(7.57+1.36)=32.36﹣13.43﹣7.57﹣1.36=32.36﹣1.36﹣(13.43+7.57)=31﹣21=1③7.2×2.745÷0.36=7.2÷0.36×2.745=20×2.745=54.9④3.85×5.6+5.4×3.85﹣3.85 =3.85×(5.6+5.4﹣1)=3.85×10=38.5⑤(3.2+0.128)÷0.8 =3.2÷0.8+0.128÷0.8=4+0.16=4.16⑥(13.3﹣8.8)×3.2÷0.36=4.5×3.2÷0.36=14.4÷0.36=4034.【解答】解:①0.75×4×0.25×4=(0.75×4)×(0.25×4)=3×1=3 ②6.3×10.1=6.3×(10+0.1)=6.3×10+6.3×0.1=63+0.63=63.63③15.58÷8.2﹣0.72=1.9﹣0.72=1.18 ④4.536÷0.8÷14=5.67÷14=0.40535.【解答】解:(1)7.5×2+1.25÷0.5=15+2.5=17.5;(2)98×7.5=(100﹣2)×7.5=100×7.5﹣2×7.5=750﹣15=735;(3)80÷0.25+0.75=320+0.75=320.75;(4)19×3.8+3.8=(19+1)×3.8=20×3.8=76;(5)1.25×3.4×0.8=1.25×0.8×3.4=1×3.4=3.4;(6)5.12÷0.4÷2.5=5.12÷(0.4×2.5)=5.12÷1=5.12.36.【解答】解:(1)55.04+12.8﹣3.3=67.84﹣3.3=64.54;(2)0.25×32×0.125=0.25×(4×8)×0.125=(0.25×4)×(8×0.125)=1×1=1;(3)7.8×75+75×0.2=(7.8+0.2)×75=8×75=600.37.【解答】解:(1)0.21×14÷0.5=2.94÷0.5=5.88;(2)0.25×13×4=0.25×4×13=1×13=13;(3)1.25×9.7﹣1.25×1.7=1.25×(9.7﹣1.7)=1.25×8=10;(4)16.5÷[(5.2+4.8)×1.5]=16.5÷[10×1.5]=16.5÷15=1.1;(5)(8.92﹣0.45)÷(2.5+4.5)=8.47÷7=1.21.38.【解答】解:(1)6.8×0.46+0.54=3.128+0.54=3.668;(2)5.4×2.3+5.4×7.7=5.4×(2.3+7.7)=5.4×10=54;(3)0.25×32×12.5=0.25×(4×8)×12.5=(0.25×4)×(8×12.5)=1×100=100;(4)75÷1.25÷8=75÷(1.25×8)=75÷10=7.5.39.【解答】解:①7.8﹣7.2+0.9 =0.6+0.9=1.5②0.38+0.26+3.4 =0.64+3.4=4.04③(125﹣45)×3=80×3=240④13+[(41+22)÷9]=13+[63÷9]=13+7=20⑤6.7+2.5+3.3=(6.7+3.3)+2.5=10+2.5=12.5⑥13×25×4=13×(25×4)=13×100=130040.【解答】解:(1)12.8+2.04×9.5=12.8+19.38=32.18;(2)0.15×1999+0.15=0.15×(1999+1)=0.15×2000=300;(3)0.76×6.5﹣0.76×5.5=0.76×(6.5﹣5.5)=0.76×1=0.76;(4)78÷0.25÷0.4=78÷(0.25×0.4)=78÷0.1=780.41.【解答】解:(1)4.05÷0.5+10.75 =8.1+10.75=18.85;(2)6.8×2.7+2.7×3.2 =(6.8+3.2)×2.7=10×2.7=27;(3)6.8×0.75÷0.5=5.1÷0.5=10.2;(4)70.3﹣17.48÷7.6 =70.3﹣2.3=68;(5)8.5×1.2÷3.4 =10.2÷3.4=3;(6)13.75÷0.125﹣2.7=110﹣2.7=107.3.42.【解答】解:(1)0.75×18÷0.15=13.5÷0.15=90;(2)6.15÷0.125÷0.8=6.15÷(0.125×0.8)=6.15÷0.1=61.5;(3)4.55÷0.28﹣0.47=16.25﹣0.47=15.78;(4)1.7×2.5×0.08=1.7×(2.5×0.08)=1.7×0.2=0.34;(5)1.89×11﹣1.89=1.89×(11﹣1)=1.89×10=18.9;(6)3.6×0.35+6.4×0.35=(3.6+6.4)×0.35=10×0.35=3.5.43.【解答】解:(1)3.4+6.6÷0.3=3.4+22=25.4;(2)25×1.25×0.04×0.8=(25×0.04)×(1.25×0.8)=1×1=1;(3)99×0.73+7.3×0.1=99×0.73+0.73×1=(99+1)×0.73=100×0.73=73;(4)96.5÷1.25÷0.8=96.5÷(1.25×0.8)=96.5÷1=96.5.44.【解答】解:(1)82.4﹣12.4×5=82.4﹣62=20.4;(2)18.5﹣3.21﹣4.79=18.5﹣(3.21+4.79)=18.5﹣8=10.5;(3)8.4+3.8+1.6+6.2=8.4+1.6+3.8+6.2=(8.4+1.6)+(3.8+6.2)=10+10=20;(4)0.25×17.3×0.4 =0.25×0.4×17.3 =0.1×17.3=1.73;(5)7.2×(10+0.1)=7.2×10+7.2×0.1=72+0.72=72.72;(3)3.54×0.29﹣0.29×2.54=(3.54﹣2.54)×0.29=1×0.29=0.29.45.【解答】解:(1)0.125×32=0.125×(8×4)=(0.125×8)×4=1×4=4;(2)8.8÷0.25÷4=8.8÷(0.25×4)=8.8÷1=8.8;(3)56.5×99+56.5=56.5×(99+1)=56.5×100=5650;(4)0.78×101=0.78×(100+1)=0.78×100+0.78×1=78+0.78=78.78;(5)9.9﹣2.07÷2.3=9.9﹣0.9=9;(6)12.75÷[14.6﹣(1.3+8.2)]=12.75÷[14.6﹣9.5]=12.75÷5.1=2.5.46.【解答】解:(1)60.8﹣36÷3.6=60.8﹣10=50.8;(2)12.5×7.2×0.8=12.5×0.8×7.2=10×7.2=72;(3)99×78.5+78.5=(99+1)×78.5=100×78.5=7850;(4)24.6﹣8.9﹣1.1=24.6﹣(8.9+1.1)=24.6﹣10=14.6;(5)0.9+9.9+99.9+999.9=(0.1+0.1+0.1+0.6)+9.9+99.9+999.9=(0.1+9.9)+(0.1+99.9)+(0.1+999.9)+0.6=10+100+1000+0.6=1110.6;(6)695÷25÷4=695÷(25×4)=695÷100=6.95.47.【解答】解:(1)5.8+6.3÷9×0.5=5.8+0.7×0.5=5.8+0.35=6.15;(2)1.25×0.8÷1.25×0.8=(1.25÷1.25)×(0.8×0.8)=1×0.64=0.64;(3)1.92÷0.12﹣2.7=16﹣2.7=13.3;(4)2.65×1.7+1.35×1.7﹣1.7=(2.65+1.35﹣1)×1.7=3×1.7=5.1;(5)138÷0.25÷4=138÷(0.25×4)=138÷1=138;(6)1.25×2.5×3.2=1.25×2.5×(4×0.8)=(1.25×0.8)×(2.5×4)=1×10=10.48.【解答】解:(1)25×5+74×5+5 =(25+74+1)×5=100×5=500(2)6.74+12.62+24.38+3.26=(6.74+3.26)+(12.62+24.38)=10+37=47(3)87﹣2.123﹣0.877 =87﹣(2.123+0.877)=87﹣3=84(4)30.65﹣(7.65+5.4)=30.65﹣7.65﹣5.4=23﹣5.4=17.6(5)(40+8)×125=40×125+8×125=6000+1000=7000(6)32×38+32×62=32×(38+62)=32×100=320049.【解答】解:(1)65×102 =65×(100+2)=65×100+65×2=6500+130=6630(2)8.23﹣(2.67+3.23)=8.23﹣2.67﹣3.23 =(8.23﹣3.23)﹣2.67=5﹣2.67=2.33(3)32×16+14×32=32×(16+14)=32×30=960(4)8.46+7.26+1.51+2.84 =(8.46+1.51)+(7.26+2.84)=10+10.1=20.1(5)27×[(263+37)÷50]=27×[300÷50]=27×6=162(6)125×32×25=125×8×4×25=(125×8)×(4×25)=1000×100=10000050.【解答】解:(1)5.6×0.25 =(1.4×4)×0.25=1.4×(4×0.25)=1.4×1=1.4(2)0.32×0.25×12.5 =(0.8×0.4)×0.25×12.5=(0.8×12.5)×(0.4×0.25)=10×0.1=1 (3)6.4÷(0.3×2+0.2)=6.4÷(0.6+0.2)=6.4÷0.8=8(4)201×6.5﹣6.5 =(201﹣1)×6.5=200×6.5=1300(5)102×4.5 =(100+2)×4.5=100×4.5+2×4.5=450+9=459 (6)2.2×0.25+2.8×0.25=(2.2+2.8)×0.25=5×0.25=1.25。

小数除法脱式运算+简算300道(含答案)

小数除法脱式运算+简算300道(含答案)

⼩数除法脱式运算+简算300道(含答案)⼩数除法脱式运算+简算300道⼀.计算题(共50⼩题)1.⽤递等式进⾏计算,能简便的要简便简便计算.7.29×4.6+46×1.271 (28.7﹣18.6÷3.1)×0.8 16﹣5.32﹣4.68 3.7×0.125+6.3÷8 40.8+14.7÷(14.6﹣12.5)0.72+9.6÷3.2 2.⽤简便⽅法计算.3.7×4.5﹣4.4×3.70.25×0.25×4 3.84﹣1.9+0.16﹣1.19﹣7÷2.5×0.4 5.5×[0.672÷(2+2.2)]3.⽤递等式计算,能简算的要简算.28.7÷7×4.59.6÷(15.4﹣12.2)4.6×1.2+2.8×4.693÷3.1÷0.34.计算下列各题(能⽤简便算法的要⽤简便算法).(4.15+0.65)×0.9 9.06×14.7+5.3×9.06(2.3+1.05÷2.1)×2.5 9.18÷[(5.9﹣2.3)×0.25].5.选择合理的⽅法进⾏计算,并写出计算主要过程.12.5×0.5×8 17.5÷(5.7﹣3.2)48.77﹣32.76÷8.410.25÷2.5÷0.4 18.1﹣2.8×4.6 3.01×101﹣30.1×0.1.6.脱式计算,能简算的要简算.4.8÷2.04÷2.4 1.1÷(22÷5)25÷40×0.472+0.9÷0.125 17.37÷0.45﹣3.86÷0.1 9.07﹣22.78÷3.4+3.7.7.⽤递等式计算,能简算的要简算.10.01×101﹣10.01 0.11×1.8+8.2×0.1126×20.2﹣8.4﹣1.8 12.05÷1.25÷0.8.8.递等式计算(能简算的要简算)6.5×99 4.65﹣2.55﹣1.45 2.2×0.25+2.8×0.25 0.25×6.82×4.9.计算下⾯各题,能简算的要简算.102×4.5 8×(20﹣1.25)8.3+8.3×99 (1.25+12.5+125)×8.10.计算(能简算要简算)2.64+8.67+7.36+11.33 2.74×9.5+0.5×2.7(2400﹣480×2.5)÷1.616.8×10.1 1.25×88 6.87×[40÷(3.49﹣3.09)].11.脱式计算(能简简的要简算)2.8+0.2﹣2.8+0.2 37÷12.5÷0.8 1.25×(10+0.8)10.8﹣3.8×0.4÷0.76 0.36÷[(6.1﹣4.6)×0.8].12.计算下⾯各题,能简算的要简算.4.05÷0.9+5.5 3.67×10.1﹣3.67×0.199×0.73+0.73 3.3+6.7×3.5.13.怎样简便怎样算3.7÷2.5÷0.40.25×1.25×329.83×1.5+0.617×15.14.计算下⾯各题.(能简算的要简算)12.13+7.5﹣12.13 7.69﹣(3.7+2.69)7.8×1.019.4×3.2+6×0.32 12.5×3.2 13.8÷(1.38×2)15.下⾯各题,怎样简便就怎样算432.5÷25÷0.4 1.25×3.2×2.5 0.81×99+0.815.9×10.1 100﹣52.8﹣47.2(4﹣0.4)×0.25.16.计算下⾯各题,能简算的要简算.0.75×18÷0.15 9.3÷0.125÷8 1.78×99+1.784.7×4.28+5.3×4.28 2.3×10.2 21.36÷0.2﹣25.9.17.怎样简便就怎样计算28.4×99+28.4 3.6×2010.94×2.5﹣0.454×0.8×12.5×2.517.5÷0.25×17+1315.58÷8.2﹣0.72.18.计算,能简算的要简算.1.25×2.5×0.8×43=10÷0.2÷2.5=8.4÷0.21÷0.5=64×4.5+3.6×45= 1.25×3.2×0.8=14.5×102=19.脱式计算,能简算的要简算.0.34×101 8.8×1.25 2.94×6.3+3.7×2.9421.9﹣9.28﹣10.72 2.7+(11.2﹣2.7)×0.4 1.5×[0.02÷(2.1﹣2.09)].20.计算下⾯各题.(能简算的要简算)10.7﹣22.78÷3.4 5.5×17.3+6.7×5.5 3.76÷0.4÷2.5 0.25×12.5×3.2.21.递等式计算,能简便计算的要简便计算.4.6×25 3.75÷12.5÷0.8 2.5+7.5÷4(3.2﹣1.4)÷0.18﹣1.87.9×7.1+2.9×7.9(30.2﹣4.6×5)÷0.12.22.下⾯各题,怎样简便就怎样计算.0.75×0.5×0.8 5.6×15.7+9.3×5.6 50.4×1.9﹣1.8.23.计算下⾯各题,注意运⽤简便⽅法.2.4﹣0.2÷5×60 0.25×6.8×405.52﹣0.55﹣0.45 0.49×7.2﹣7.2×0.39.24.计算,能简算的要写出简算过程.4×0.8×2.5×12.5 2.25×4.8+77.5×0.48.25.计算下⾯各题,能简算的要简算.13.73+6.27÷0.318÷0.4÷2.5 0.75×99+0.752.85×5.35+2.85×4.65 1.5×0.4÷1.5×0.4.26.怎样简便就怎样计算28.4×99+28.4 3.6×201 0.94×2.5﹣0.454×0.8×12.5×2.5 17.5÷0.25×17+13 1.25×8.08.27.下⾯各题,怎样算简便就怎样算.2.45﹣(1.45+0.89) 1.25×1.7×0.8 5.3×0.82﹣0.82×0.33.6÷[12×(0.53﹣0.45)].28.计算下⾯各题,能简算的要简算.125×32×2.5 2.6×(3.4+1.6) 6.7×5.5+5.5×3.3.36×999.07﹣2.2﹣7.817.6÷4÷2.529.计算下⾯各题,能简算的要简算.2.5×0.27×4 0.63×101 0.78+0.22÷53.7×12.5+4.3×12.5 (0.36+5.4)÷0.6 4.5÷0.25÷1.6.30.脱式计算(能简便的⽤简便计算).1.6×(2.25+10.5÷1.5)74×57+43×740.6÷[(6.1﹣4.6)×0.8]101×92﹣92125×64 46.2×0.56+5.37×5.6+1×0.05631.脱式计算(能简算的就简算)1.5×102 1.25×213×0.8 72×0.81﹢10.41.25×5.6 6.05÷0.5+10.75 29.6÷0.8﹣1.2×5.32.脱式计算下列各题,能简算的要简算.2.69×99+2.69 1.25×2.3×0.83.17×5.6+4.4×3.1738÷0.25÷0.4 6.5÷0.125 0.225÷0.25×433.脱式计算(能简算的要简算).17.54+28.35+3.46+1.55 32.36﹣13.43﹣(7.57+1.36)7.2×2.745÷0.363.85×5.6+5.4×3.85﹣3.85 (3.2+0.128)÷0.8 (13.3﹣8.8)×3.2÷0.36.34.脱式计算(能简算的要简算)0.75×4×0.25×4 6.3×10.115.58÷8.2﹣0.72 4.536÷0.8÷14.35.脱式计算,能简算的要简算.7.5×2+1.25÷0.598×7.580÷0.25+0.75 19×3.8+3.8 1.25×3.4×0.8 5.12÷0.4÷2.536.计算,能简算的要简算55.04+12.8﹣3.30.25×32×0.1257.8×75+75×0.2.37.⽤你喜欢的⽅法计算.0.21×14÷0.50.25×13×4 1.25×9.7﹣1.25×1.716.5÷[(5.2+4.8)×1.5](8.92﹣0.45)÷(2.5+4.5)38.下⾯各题怎样算简便就怎样算.6.8×0.46+0.54 5.4×2.3+5.4×7.70.25×32×12.5 75÷1.25÷8.39.⽤递等式计算,(有★⽤简算)7.8﹣7.2+0.9 0.38+0.26+3.4 (125﹣45)×313+[(41+22)÷9]★6.7+2.5+3.3★13×25×4.40.脱式计算,能简算的要简算12.8+2.04×9.50.15×1999+0.150.76×6.5﹣0.76×5.578÷0.25÷0.4.41.计算下⾯各题,怎样简便就怎样计算.4.05÷0.5+10.75 6.8×2.7+2.7×3.2 6.8×0.75÷0.570.3﹣17.48÷7.6 8.5×1.2÷3.4 13.75÷0.125﹣2.7.42.计算下⾯各题,能⽤简便⽅法计算的要⽤简便⽅法.0.75×18÷0.15 6.15÷0.125÷0.8 4.55÷0.28﹣0.471.7×2.5×0.08 1.89×11﹣1.893.6×0.35+6.4×0.3543.计算下⾯各题,能简算的要简算.3.4+6.6÷0.3 25×1.25×0.04×0.899×0.73+7.3×0.1 96.5÷1.25÷0.8.44.脱式计算(能简算的⽤简算⽅法)82.4﹣12.4×5 18.5﹣3.21﹣4.79 8.4+3.8+1.6+6.20.25×17.3×0.4 7.2×(10+0.1) 3.54×0.29﹣0.29×2.5445.计算下列各题,怎么简便就怎么算.0.125×32 8.8÷0.25÷4 56.5×99+56.50.78×1019.9﹣2.07÷2.312.75÷[14.6﹣(1.3+8.2)].46.计算,能简算的要简算.60.8﹣36÷3.6 12.5×7.2×0.899×78.5+78.5 24.6﹣8.9﹣1.10.9+9.9+99.9+999.9 695÷25÷4.47.脱式计算(能简算的要简算)5.8+6.3÷9×0.5 1.25×0.8÷1.25×0.8 1.92÷0.12﹣2.72.65×1.7+1.35×1.7﹣1.7138÷0.25÷4 1.25×2.5×3.248.你能想出简便⽅法来计算下⾯各题吗?25×5+74×5+5 6.74+12.62+24.38+3.2687﹣2.123﹣0.877 30.65﹣(7.65+5.4)(40+8)×125 32×38+32×62.49.脱式计算.(能简算的要简算)65×102 8.23﹣(2.67+3.23)32×16+14×32 8.46+7.26+1.51+2.84 27×[(263+37)÷50]125×32×25.50.递等式计算(能简算的要简算)5.6×0.25 0.32×0.25×12.56.4÷(0.3×2+0.2)201×6.5﹣6.5 102×4.5 2.2×0.25+2.8×0.25.⼩数除法脱式运算+简算300道参考答案与试题解析⼀.计算题(共50⼩题)1.【解答】解:①7.29×4.6+46×1.271 =7.29×4.6+4.6×12.71=(7.29+12.71)×4.6=20×4.6=92;②(28.7﹣18.6÷3.1)×0.8 =(28.7﹣6)×0.8=22.7×0.8=18.16;③16﹣5.32﹣4.68=16﹣(5.32+4.68)=16﹣10=6;④3.7×0.125+6.3÷8 =3.7×+6.3×=(3.7+6.3)×=10×=;⑤40.8+14.7÷(14.6﹣12.5)=40.8+14.7÷2.1=40.8+7=47.8;⑥0.72+9.6÷3.2=0.72+3=3.72.2.【解答】解:(1)3.7×4.5﹣4.4×3.7=3.7×(4.5﹣4.4)=3.7×0.1=0.37;(2)0.25×0.25×4=0.25×(0.25×4)=0.25×1=0.25;(3)3.84﹣1.9+0.16﹣1.1=(3.84+0.16)﹣(1.9+1.1)=4﹣3=1;(4)9﹣7÷2.5×0.4=9﹣2.8×0.4=9﹣1.12=7.88;(5)5.5×[0.672÷(2+2.2)]=5.5×[0.672÷4.2]=5.5×0.16=0.88.3.【解答】解:(1)28.7÷7×4.5=4.1×4.5=18.45(2)9.6÷(15.4﹣12.2)=9.6÷3.2=3(3)4.6×1.2+2.8×4.6=4.6×(1.2+2.8)=4.6×4=18.4(4)93÷3.1÷0.3=30÷0.3=1004.【解答】解:(1)(4.15+0.65)×0.9=4.8×0.9=4.32;(2)9.06×14.7+5.3×9.06=9.06×(14.7+5.3)=9.06×20=181.2;(3)(2.3+1.05÷2.1)×2.5=(2.3+0.5)×2.5=2.8×2.5=7;(4)9.18÷[(5.9﹣2.3)×0.25]=9.18÷[3.6×0.25]=9.18÷0.9=10.2.5.【解答】解:(1)12.5×0.5×8=12.5×8×0.5=100×0.5=50;(2)17.5÷(5.7﹣3.2)=17.5÷2.5=7;(3)48.77﹣32.76÷8.4=48.77﹣3.9=44.87;(4)10.25÷2.5÷0.4=10.25÷(2.5×0.4)=10.25÷1=10.25;(5)18.1﹣2.8×4.6=18.1﹣12.88=5.22;(6)3.01×101﹣30.1×0.1=3.01×(101﹣1)=30.1×100=30100.6.【解答】解:(1)4.8÷2.04÷2.4=4.8÷2.4÷2.04=2÷2.04=(2)1.1÷(22÷5)=1.1÷22×5=0.05×5=0.25(3)25÷40×0.4=25×0.4÷40=10÷40=0.25(4)72+0.9÷0.125=72+7.2=79.2(5)17.37÷0.45﹣3.86÷0.1=38.6﹣38.6=0(6)9.07﹣22.78÷3.4+3.7=9.07﹣6.7+3.7=2.37+3.7=6.077.【解答】解:(1)10.01×101﹣10.01=10.01×(101﹣1)=10.01×100=1001(2)0.11×1.8+8.2×0.11=0.11×(1.8+8.2)=0.11×10=1.1(3)26×20.2﹣8.4﹣1.8=525.2﹣(8.4+1.8)=525.2﹣10.2=515(4)12.05÷1.25÷0.8=12.05÷(1.25×0.8)=12.05÷1=12.058.【解答】解:①6.5×99=6.5×(100﹣1)=6.5×100﹣6.5=650﹣6.5=643.5②4.65﹣2.55﹣1.45=4.65﹣(2.55+1.45)=4.65﹣4=0.65③2.2×0.25+2.8×0.25=(2.2+2.8)×0.25=5×0.25=1.25④0.25×6.82×4=(0.25×4)×6.82=1×6.82=6.829.【解答】解:①102×4.5=(100+2)×4.5=100×4.5+2×4.5=450+9=459②8×(20﹣1.25)=8×20﹣8×1.25=160﹣10=150③8.3+8.3×99 =8.3×(1+99)=8.3×100=830④(1.25+12.5+125)×8=1.25×8+12.5×8+125×8=10+100+1000=110+1000=111010.【解答】解:①2.64+8.67+7.36+11.33=(2.64+7.36)+(8.67+11.33)=10+20=30②2.74×9.5+0.5×2.7=26.03+1.35=27.38③(2400﹣480×2.5)÷1.6=(2400﹣1200)÷1.6=1200÷1.6=750④16.8×10.1=16.8×(10+0.1)=16.8×10+16.8×0.1=168+1.68=169.68⑤1.25×88=1.25×(80+8)=1.25×80+1.25×8=100+10=110⑥6.87×[40÷(3.49﹣3.09)]=6.87×[40÷0.4]=6.87×100=68711.【解答】解:(1)2.8+0.2﹣2.8+0.2=(2.8﹣2.8)+(0.2+0.2)=0+0.4=0.4(2)37÷12.5÷0.8=37÷(12.5×0.8)=37÷10=3.7(3)1.25×(10+0.8)=1.25×10+1.25×0.8=12.5+1=13.5(4)10.8﹣3.8×0.4÷0.76=10.8﹣1.52÷0.76=10.8﹣2=8.8(5)0.36÷[(6.1﹣4.6)×0.8]=0.36÷[1.5×0.8]=0.36÷1.2=0.3 12.【解答】解:(1)4.05÷0.9+5.5=4.5+5.5=10(2)3.67×10.1﹣3.67×0.1=3.67×(10.1﹣0.1)=3.67×10=36.7(3)99×0.73+0.73=(99+1)×0.73=100×0.73=73(4)3.3+6.7×3.5=3.3+23.45=26.7513.【解答】解:①3.7÷2.5÷0.4=3.7÷(2.5×0.4)=3.7÷1=3.7②0.25×1.25×32=0.25×1.25×(4×8)=(0.25×4)×(1.25×8)=1×10=10③9.83×1.5+0.617×15=9.83×1.5+6.17×1.5=1.5×(9.83+6.17)=1.5×16=2414.【解答】解:①12.13+7.5﹣12.13=12.13﹣12.13+7.5=0+7.5=7.5 ②7.69﹣(3.7+2.69)=7.69﹣3.7﹣2.69=7.69﹣2.69﹣3.7=5﹣3.7=1.3③7.8×1.01=7.8×(1+0.01)=7.8×1+7.8×0.01=7.8+0.078=7.878④9.4×3.2+6×0.32=9.4×3.2+0.6×3.2=3.2×(9.4+0.6)=3.2×10=32 ⑤12.5×3.2=12.5×(8×0.4)=12.5×8×0.4=100×0.4=40 ⑥13.8÷(1.38×2)=13.8÷1.38÷2=10÷2=515.【解答】解:①432.5÷25÷0.4=432.5÷(25×0.4)=432.5÷10=43.25②1.25×3.2×2.5=1.25×(8×0.4)×2.5=(1.25×8)×(0.4×2.5)=10×1=10③0.81×99+0.81=0.81×(99+1)=0.81×100=81④5.9×10.1=5.9×(10+0.1)=5.9×10+5.9×0.1=59+0.59=59.59⑤100﹣52.8﹣47.2=100﹣(52.8+47.2)=100﹣100=0⑥(4﹣0.4)×0.25=4×0.25﹣0.4×0.25=1﹣0.1=0.916.【解答】解:(1)0.75×18÷0.15=0.75÷0.15×18=5×18=90;(2)9.3÷0.125÷8 =9.3÷(0.125×8)=9.3÷1=9.3;(3)1.78×99+1.78=1.78×(99+1)=1.78×100=178;(4)4.7×4.28+5.3×4.28 =(4.7+5.3)×4.28=10×4.28=42.8;(5)2.3×10.2 =2.3×(10+0.2)=2.3×10+2.3×0.2=23+0.46=23.46;(6)21.36÷0.2﹣25.9=106.8﹣25.9=80.9.17.【解答】解:(1)28.4×99+28.4=28.4×(99+1)=28.4×100=2840(2)3.6×201=3.6×(200+1)=3.6×200+3.6×1=720+3.6=723.6(3)0.94×2.5﹣0.45=2.35﹣0.45=1.9(4)4×0.8×12.5×2.5=(4×2.5)×(0.8×12.5)=10×10=100(5)17.5÷0.25×17+13=70×17+13=1190+13=1203(6)15.58÷8.2﹣0.72=1.9﹣0.72=1.1818.【解答】解:(1)1.25×2.5×0.8×43=1.25×0.8×2.5×43=1×2.5×43=107.5;(2)10÷0.2÷2.5=10÷(0.2×2.5)=10÷0.5=20;(3)8.4÷0.21÷0.5=40÷0.5=80;(4)64×4.5+3.6×45=64×4.5+36×4.5=(64+36)×4.5=100×4.5=450;(5)1.25×3.2×0.8=1.25×0.8×3.2=1×3.2=3.2;(6)14.5×102=14.5×(100+2)=14.5×100+14.5×2=1450+29=1479.19.【解答】解:(1)0.34×101=0.34×(100+1)=0.34×100+0.34×1=34+0.34=34.34;(2)8.8×1.25=(1.1×8)×1.25=1.1×(8×1.25)=1.1×10=11;(3)2.94×6.3+3.7×2.94=2.94×(6.3+3.7)=2.94×10=29.4;(4)21.9﹣9.28﹣10.72=21.9﹣(9.28+10.72)=21.9﹣20=1.9;(5)2.7+(11.2﹣2.7)×0.4=2.7+8.5×0.4=2.7+3.4=6.1;(6)1.5×[0.02÷(2.1﹣2.09)]=1.5×[0.02÷0.01]=1.5×2=3.20.【解答】解:①10.7﹣22.78÷3.4 =10.7﹣6.7=4②5.5×17.3+6.7×5.5=5.5×(17.3+6.7)=5.5×24=132③3.76÷0.4÷2.5=3.76÷(0.4×2.5)=3.76÷1=3.76 ④0.25×12.5×3.2=0.25×12.5×(4×0.8)=(0.25×4)×(12.5×0.8)=1×10=1021.【解答】解:(1)4.6×25=(4+0.6)×25=4×25+0.6×25=100+15=115;(2)3.75÷12.5÷0.8=3.75÷(12.5÷0.8)=3.75÷10=0.375;(3)2.5+7.5÷4=2.5+1.875=4.375;(4)(3.2﹣1.4)÷0.18﹣1.8=1.8÷0.18﹣1.8=10﹣1.8=8.2;(5)7.9×7.1+2.9×7.9=7.9×(7.1+2.9)=7.9×10=79;(6)(30.2﹣4.6×5)÷0.12=(30.2﹣23)÷0.12=7.2÷0.12=60.22.【解答】解:(1)0.75×0.5×0.8=0.75×(0.5×0.8)=0.75×0.4=0.3;(2)5.6×15.7+9.3×5.6=5.6×(15.7+9.3)=5.6×25=14×0.4×25=14×(0.4×25)=14×10=140;(3)50.4×1.9﹣1.8=95.76﹣1.8=93.96.23.【解答】解:①2.4﹣0.2÷5×60=2.4﹣0.04×60=2.4﹣2.4=0②0.25×6.8×40=(0.25×40)×6.8=10×6.8=68③5.52﹣0.55﹣0.45=5.52﹣(0.55+0.45)=5.52﹣1=4.52④0.49×7.2﹣7.2×0.39=7.2×(0.49﹣0.39)=7.2×0.1=0.7224.【解答】解:(1)4×0.8×2.5×12.5=(4×2.5)×(0.8×12.5)=10×10=100(2)×14+87×﹣=×(14+87﹣1)=×100=80(3)(+)×42 =×42+×42=35+12=47(4)2.25×4.8+77.5×0.48=2.25×4.8+7.75×4.8=(2.25+7.75)×4.8=10×4.8=48 25.【解答】解:(1)13.73+6.27÷0.3=13.73+20.9=34.63;(2)18÷0.4÷2.5=18÷(0.4×2.5)=18÷1=18;(3)0.75×99+0.75=0.75×(99+1)=0.75×100=75;(4)2.85×5.35+2.85×4.65=2.85×(5.35+4.65)=2.85×10=28.5;(5)1.5×0.4÷1.5×0.4=1.5÷1.5×0.4×0.4=1×0.4×0.4=0.4×0.4=0.16.26.【解答】解:(1)28.4×99+28.4=28.4×(99+1)=28.4×100=2840;(2)3.6×201=3.6×(200+1)=3.6×200+3.6×1=720+3.6=723.6;(3)0.94×2.5﹣0.45=2.35﹣0.45=1.9;(4)4×0.8×12.5×2.5=(4×2.5)×(0.8×12.5)=10×10=100;(5)17.5÷0.25×17+13=70×17+13=1190+13=1203;(6)1.25×8.08=1.25×(8+0.08)=1.25×8+1.25×0.08=10+0.1=10.1.27.【解答】解:①2.45﹣(1.45+0.89)=2.45﹣1.45﹣0.89=1﹣0.89=0.11②1.25×1.7×0.8=1.25×0.8×1.7=1×1.7=1.7③5.3×0.82﹣0.82×0.3=0.82×(5.3﹣0.3)=0.82×5=4.1 ④3.6÷[12×(0.53﹣0.45)]3.6÷12÷(0.53﹣0.45)=0.3÷0.08=3.7528.【解答】解:(1)125×32×2.5=125×(4×8)×2.5=(125×8)×(4×2.5)=1000×10=10000;(2)2.6×(3.4+1.6)=2.6×5=13;(3)6.7×5.5+5.5×3.3=(6.7+3.3)×5.5=10×5.5=55;(4)36×99=36×(100﹣1)=36×100﹣36×1=3600﹣36=3564;(5)9.07﹣2.2﹣7.8=9.07﹣(2.2+7.8)=9.07﹣10=﹣0.93;(6)17.6÷4÷2.5=17.6÷(4×2.5)=17.6÷10=1.76.29.【解答】解:(1)2.5×0.27×4=2.5×4×0.27=10×0.27=2.7;(2)0.63×101=0.36×(100+1)=0.36×100+0.36×1=36+0.36=36.36;(3)0.78+0.22÷5=0.78+0.044=0.824;(4)3.7×12.5+4.3×12.5=(3.7+4.3)×12.5=8×12.5=100;(5)(0.36+5.4)÷0.6=5.76÷0.6=9.6;(6)4.5÷0.25÷1.6=4.5÷(0.25×1.6)=4.5÷0.4=11.25.30.【解答】解:(1)1.6×(2.25+10.5÷1.5)=1.6×(2.25+7)=1.6×9.25=14.8;(2)74×57+43×74=74×(57+43)=74×100=7400;(3)0.6÷[(6.1﹣4.6)×0.8]=0.6÷[1.5×0.8]=0.6÷1.2=0.5;(4)101×92﹣92=(101﹣1)×92=100×92=9200;(5)125×64 =125×8×8=1000×8=8000;(6)46.2×0.56+5.37×5.6+1×0.056=4.62×5.6+5.37×5.6+0.01×5.6=(4.62+5.37+0.01)×5.6=10×5.6=56.31.【解答】解:①1.5×102=1.5×(100+2)=1.5×100+1.5×2=150+3=153②1.25×213×0.8=1.25×0.8×213=1×213=213 ③72×0.81﹢10.4=58.32+10.4=68.72④1.25×5.6 =1.25×(8×0.7)=1.25×8×0.7=10×0.7=7⑤6.05÷0.5+10.75=12.1+10.75=22.85⑥29.6÷0.8﹣1.2×5=37﹣6=31 32.【解答】解:(1)2.69×99+2.69=2.69×(99+1)=2.69×100=269(2)1.25×2.3×0.8=1.25×0.8×2.3=1×2.3=2.3(3)3.17×5.6+4.4×3.17=3.17×(5.6+4.4)=3.17×10=31.7(4)38÷0.25÷0.4=38÷(0.25×0.4)=38÷0.1=380(5)60.125=6.5÷=6.5×8=52(6)0.225÷0.25×4=0.9×4=3.633.【解答】解:①17.54+28.35+3.46+1.55=17.54+3.46+(28.35+1.55)=21+29.9=50.9 ②32.36﹣13.43﹣(7.57+1.36)=32.36﹣13.43﹣7.57﹣1.36=32.36﹣1.36﹣(13.43+7.57)=31﹣21=1③7.2×2.745÷0.36=7.2÷0.36×2.745=20×2.745=54.9④3.85×5.6+5.4×3.85﹣3.85 =3.85×(5.6+5.4﹣1)=3.85×10=38.5⑤(3.2+0.128)÷0.8 =3.2÷0.8+0.128÷0.8=4+0.16=4.16⑥(13.3﹣8.8)×3.2÷0.36=4.5×3.2÷0.36=14.4÷0.36=4034.【解答】解:①0.75×4×0.25×4=(0.75×4)×(0.25×4)=3×1=3②6.3×10.1=6.3×(10+0.1)=6.3×10+6.3×0.1=63+0.63=63.63③15.58÷8.2﹣0.72=1.9﹣0.72=1.18 ④4.536÷0.8÷14=5.67÷14=0.40535.【解答】解:(1)7.5×2+1.25÷0.5=15+2.5=17.5;(2)98×7.5=(100﹣2)×7.5=100×7.5﹣2×7.5=750﹣15=735;(3)80÷0.25+0.75=320+0.75=320.75;(4)19×3.8+3.8=(19+1)×3.8=20×3.8=76;(5)1.25×3.4×0.8=1.25×0.8×3.4=1×3.4=3.4;(6)5.12÷0.4÷2.5=5.12÷(0.4×2.5)=5.12÷1=5.12.36.【解答】解:(1)55.04+12.8﹣3.3=67.84﹣3.3=64.54;(2)0.25×32×0.125=0.25×(4×8)×0.125=(0.25×4)×(8×0.125)=1×1=1;(3)7.8×75+75×0.2=(7.8+0.2)×75=8×75=600.37.【解答】解:(1)0.21×14÷0.5=2.94÷0.5=5.88;(2)0.25×13×4=0.25×4×13=1×13=13;(3)1.25×9.7﹣1.25×1.7=1.25×(9.7﹣1.7)=1.25×8=10;(4)16.5÷[(5.2+4.8)×1.5]=16.5÷[10×1.5]=16.5÷15=1.1;(5)(8.92﹣0.45)÷(2.5+4.5)=8.47÷7=1.21.38.【解答】解:(1)6.8×0.46+0.54=3.128+0.54=3.668;(2)5.4×2.3+5.4×7.7=5.4×(2.3+7.7)=5.4×10=54;(3)0.25×32×12.5=0.25×(4×8)×12.5=(0.25×4)×(8×12.5)=1×100=100;(4)75÷1.25÷8=75÷(1.25×8)=75÷10=7.5.39.【解答】解:①7.8﹣7.2+0.9 =0.6+0.9=1.5②0.38+0.26+3.4 =0.64+3.4=4.04③(125﹣45)×3=80×3=240④13+[(41+22)÷9]=13+[63÷9]=13+7=20⑤6.7+2.5+3.3=(6.7+3.3)+2.5=10+2.5=12.5⑥13×25×4=13×(25×4)=13×100=130040.【解答】解:(1)12.8+2.04×9.5=12.8+19.38=32.18;(2)0.15×1999+0.15=0.15×(1999+1)=0.15×2000=300;(3)0.76×6.5﹣0.76×5.5=0.76×(6.5﹣5.5)=0.76×1=0.76;(4)78÷0.25÷0.4=78÷(0.25×0.4)=78÷0.1=780.41.【解答】解:(1)4.05÷0.5+10.75 =8.1+10.75=18.85;(2)6.8×2.7+2.7×3.2 =(6.8+3.2)×2.7=10×2.7=27;(3)6.8×0.75÷0.5=5.1÷0.5=10.2;(4)70.3﹣17.48÷7.6 =70.3﹣2.3=68;(5)8.5×1.2÷3.4=10.2÷3.4=3;(6)13.75÷0.125﹣2.7=110﹣2.7=107.3.42.【解答】解:(1)0.75×18÷0.15=13.5÷0.15=90;(2)6.15÷0.125÷0.8=6.15÷(0.125×0.8)=6.15÷0.1=61.5;(3)4.55÷0.28﹣0.47=16.25﹣0.47=15.78;(4)1.7×2.5×0.08=1.7×(2.5×0.08)=1.7×0.2=0.34;(5)1.89×11﹣1.89=1.89×(11﹣1)=1.89×10=18.9;(6)3.6×0.35+6.4×0.35=(3.6+6.4)×0.35=10×0.35=3.5.43.【解答】解:(1)3.4+6.6÷0.3=3.4+22=25.4;(2)25×1.25×0.04×0.8=(25×0.04)×(1.25×0.8)=1×1=1;(3)99×0.73+7.3×0.1=99×0.73+0.73×1=(99+1)×0.73=100×0.73=73;(4)96.5÷1.25÷0.8=96.5÷(1.25×0.8)=96.5÷1=96.5.44.【解答】解:(1)82.4﹣12.4×5=82.4﹣62=20.4;(2)18.5﹣3.21﹣4.79=18.5﹣(3.21+4.79)=18.5﹣8=10.5;(3)8.4+3.8+1.6+6.2=8.4+1.6+3.8+6.2=(8.4+1.6)+(3.8+6.2)=10+10=20;(4)0.25×17.3×0.4 =0.25×0.4×17.3 =0.1×17.3=1.73;(5)7.2×(10+0.1)=7.2×10+7.2×0.1=72+0.72=72.72;(3)3.54×0.29﹣0.29×2.54=(3.54﹣2.54)×0.29=1×0.29=0.29.45.【解答】解:(1)0.125×32=0.125×(8×4)=(0.125×8)×4=1×4=4;(2)8.8÷0.25÷4=8.8÷(0.25×4)=8.8÷1=8.8;(3)56.5×99+56.5=56.5×(99+1)=56.5×100=5650;(4)0.78×101=0.78×(100+1)=0.78×100+0.78×1=78+0.78=78.78;(5)9.9﹣2.07÷2.3=9.9﹣0.9=9;(6)12.75÷[14.6﹣(1.3+8.2)]=12.75÷[14.6﹣9.5]=12.75÷5.1=2.5.46.【解答】解:(1)60.8﹣36÷3.6=60.8﹣10=50.8;(2)12.5×7.2×0.8=12.5×0.8×7.2=10×7.2=72;(3)99×78.5+78.5=(99+1)×78.5=100×78.5=7850;(4)24.6﹣8.9﹣1.1=24.6﹣(8.9+1.1)=24.6﹣10=14.6;(5)0.9+9.9+99.9+999.9=(0.1+0.1+0.1+0.6)+9.9+99.9+999.9=(0.1+9.9)+(0.1+99.9)+(0.1+999.9)+0.6=10+100+1000+0.6=1110.6;(6)695÷25÷4=695÷(25×4)=695÷100=6.95.47.【解答】解:(1)5.8+6.3÷9×0.5=5.8+0.7×0.5=5.8+0.35=6.15;(2)1.25×0.8÷1.25×0.8=(1.25÷1.25)×(0.8×0.8)=1×0.64=0.64;(3)1.92÷0.12﹣2.7=16﹣2.7=13.3;(4)2.65×1.7+1.35×1.7﹣1.7=(2.65+1.35﹣1)×1.7=3×1.7=5.1;(5)138÷0.25÷4=138÷(0.25×4)=138÷1=138;(6)1.25×2.5×3.2=1.25×2.5×(4×0.8)=(1.25×0.8)×(2.5×4)=1×10=10.48.【解答】解:(1)25×5+74×5+5 =(25+74+1)×5=100×5=500(2)6.74+12.62+24.38+3.26=(6.74+3.26)+(12.62+24.38)=10+37=47(3)87﹣2.123﹣0.877 =87﹣(2.123+0.877)=87﹣3=84(4)30.65﹣(7.65+5.4)=30.65﹣7.65﹣5.4=23﹣5.4=17.6(5)(40+8)×125=40×125+8×125=6000+1000=7000(6)32×38+32×62=32×(38+62)=32×100=320049.【解答】解:(1)65×102=65×(100+2)=65×100+65×2=6500+130=6630(2)8.23﹣(2.67+3.23)=8.23﹣2.67﹣3.23 =(8.23﹣3.23)﹣2.67=5﹣2.67=2.33(3)32×16+14×32=32×(16+14)=32×30=960(4)8.46+7.26+1.51+2.84=(8.46+1.51)+(7.26+2.84)=10+10.1=20.1(5)27×[(263+37)÷50]=27×[300÷50]=27×6=162(6)125×32×25=125×8×4×25=(125×8)×(4×25)=1000×100=10000050.【解答】解:(1)5.6×0.25 =(1.4×4)×0.25=1.4×(4×0.25)=1.4×1=1.4(2)0.32×0.25×12.5 =(0.8×0.4)×0.25×12.5=(0.8×12.5)×(0.4×0.25)=10×0.1=1(3)6.4÷(0.3×2+0.2)=6.4÷(0.6+0.2)=6.4÷0.8=8(4)201×6.5﹣6.5 =(201﹣1)×6.5=200×6.5=1300(5)102×4.5 =(100+2)×4.5=100×4.5+2×4.5=450+9=459(6)2.2×0.25+2.8×0.25=(2.2+2.8)×0.25=5×0.25=1.25。

小数除法中的简便计算

小数除法中的简便计算

u-math Thought training Mr Hu优数思维训练小数除法简便计算一、知识概述在前面的学习中我们已经掌握了除法运算律,除法运算中的商不变规律以及一些有除法的运算律,如a÷b÷c=a÷(b×c)。

这些在整数运算中的规律同样适用于小数除法。

这一节我们专门探究小数除法中的简便计算。

二、例题精学例1用简便方法计算:(1)2.4÷0.5 (2)1.2÷2.5 (3)3.1÷0.125【思路点拨】根据被除数和除数同时乘以同一个数(零除外)商不变的规律。

某数除以1仍得某数,除以10,100,1000,…,就是把被除数的小数点向左移动一位,两位,三位的运算特性,可以使小数除法计算变得简单快捷。

同步练习:计算下列各题。

1、1.8÷0.252、3.6÷0.23、7.6÷0.125例2 用简便方法计算:(1)31.4÷2.5÷4 (2)12.5÷(12.5×4)【思路点拨】根据a÷b÷c=a÷(b×c)这一运算特性进行简便计算。

这个性质类似于一个数连续减去两个数就等于这个数减去两个减数的和即a-b-c=a-(b+c)。

同步练习:1、10.8÷1.2÷32、7.6÷(7.6×2)3、15.6÷5.2÷3例3计算:16.15÷1.8+1.85÷1.8【思路点拨】当两个除法算式中,除数相同时,可以把两个被除数相加减,再除以这个除数。

同步练习:1、15.76÷3.5+19.24÷3.52、7.6÷1.4+6.3÷1.4+2.9÷1.43、15.8÷0.3-0.8÷0.3问题探究:当两个除法算式中,被除数相同时,有没有类似的结论?例如:10.8÷6-10.8÷0.6例4计算(8.6×7.2×9.3)÷(4.3×3.6×3.1)【思路点拨】如果按照运算顺序计算,过程非常复杂,但仔细观察被除数(8.6×7.2×9.3)和除数(4.3×3.6×3.1)之间存在的倍数关系,可以分别相除,再把所得结果相乘作为最后的运算结果。

小学五年级数学小数的连除、除加、除减混合运算和简便算法

小学五年级数学小数的连除、除加、除减混合运算和简便算法

小数的连除、除加、除减混合运算和简便算法五年级数学教案教学目标1.掌握小数连除、除加、除减的运算顺序,会正确计算,并能根据题目的特点对一些小数除法进行正确的简算.2.通过对小数连除、除加、除减的运算顺序的归纳,提高学生的抽象概括能力.3.培养学生养成良好的学习习惯,提高学生的计算能力.教学重点小数连除、除加、除减的运算顺序.教学难点小数除法的简算.教学过程一、复习准备(一)口算0.8×0.5 1.6+0.38 0.15÷5 1-0.750.48÷0.03 630÷45÷2 6÷1.2 4×2.5280÷35 0.56÷14 0.92÷0.4 1.1×5教师提问:630÷45÷2 280÷35 0.56÷14是怎样口算的?为新知辅垫(二)先想一想下面各题的运算顺序,再计算.360÷4÷5 420÷6+150 750÷5-80二、探索新知(一)教学连除、除加、除减混合运算.例10.一只蜜蜂0.5小时飞行9.3千米,是一只蝴蝶飞行速度的2.4倍.这只蝴蝶每小时飞行多少千米?1.分析数量关系并列式9.3÷0.5÷2.4教师提问:9.3÷0.5求的是什么?2.尝试计算说一说运算顺序,先算什么?再算什么?3.练一练432÷3.6+2.88 2.96÷0.4-1.73教师提问:小数连除、除加、除减的运算顺序是什么?它与整数连除、除加、除减有什么联系?结论:小数连除、除加、除减的运算顺序与整数完全相同.(二)小数除法的一些简便算法1.教师:在整数除法中,我们学过了一些简便算法.360÷45÷2 560÷35教师提问:谁能说一说这两道题怎样算比较简便?2.变式3.6÷4.5÷25.6÷35(1)学生独立完成,指名板演.(2)集体订正,说出简算的方法.小结:整数除法中的简算方法在小数除法中了同样适用.3.做一做,用简便方法计算4.5÷18 930÷5÷0.6●三、课堂小结1.从这节课中你知道了什么?2.对于今天学习的知识还有什么问题或疑惑?●四、巩固新知(一)在下面的□里填上适当的数.2.1÷28=2.1÷□÷□0.78÷0.3÷0.2=0.78÷□(二)计算下面各题.(能简算的要简算)213.6÷0.8÷0.3 0.77÷3540.5÷0.5+10.75 9.728÷3.2÷197.2÷1.2÷3 18.305÷0.07÷85.76(三)对比练习13.4÷4÷2.5 35×1.6÷810.8÷3.3 3.2+0.128÷0.8(四)看算式直接写得数0.25×2.3×4 1.5÷1.5+1.5 1-0.32-0.681.4×0.5-0.7 4.5÷4.5÷2 18.4÷4÷2.33.6-2.4÷2.4 50×0.34×0.2 20×(0.1-0.05)0.1×0.2×0.3 4.6×7+3×4.6 38.5×0×0.381.25×0.4×8 0.65×101 0.5×4÷0.5×4五、板书设计小数连除、除加、除减例10.一只蜜蜂0.5小时飞行9.3千米,是一只蝴蝶飞行速度的2.4倍.这只蝴蝶每小时飞行多少千米?9.3÷0.5÷2.4=18.6÷2.4=7.75(千米)答:这只蝴蝶每小时飞行7.75千米.。

小数除法脱式运算+简算260道 含问题详解

小数除法脱式运算+简算260道  含问题详解

小数除法脱式运算+简算260道一.计算题(共50小题)1.用你喜欢的方法计算.32×12.5×0.25 6.1×4.2+5.8×6.1 1.7÷2.5÷0.416.1﹣4.2﹣5.8.3.脱式计算4.8÷(1.2÷0.5)12.8﹣12.8÷571.4÷(7×6)4.用你喜欢的方法计算0.65×101﹣0.65 12.6﹣3.25+6.756.35÷0.2÷0.5 5.7×1.2÷19 1.25×3.63×0.8.5.我能用喜欢的方法计算下面各题.0.11×1.8+8.2×0.11 3.5﹣3.5×0.980.75×18÷0.150.25×4.78×8.6.能简算的要简算.17.3÷0.125÷8 14.72×0.7+5.28×0.73.5÷0.56 8.5×9.9+0.82.7.递等式计算,有简便运算的用简便方法38.75﹣(24.5+8.75)0.4×2.32×0.250.75×101 4.2﹣3.2×0.97.56×99+7.5670.3﹣17.48÷7.6 3.64÷5.2×23.321.8÷0.8﹣1.2×5 45÷(5.25÷0.25)16.5×101﹣16.50.96÷0.3×14 1.25×4×2.5×836.45÷(0.82+3.4×0.2)9.07﹣2.64÷0.4 1.5×10112.6×7.5+8.3 13.6×0.85﹣3.6×0.85104×8.586.4÷6.4﹣0.40.25×6.2×0.423×6.5+17×6.536÷0.4×0.25(24.6﹣18.1)×3.47.6×9.9+7.6×0.1 13.6×0.8×12.523.9×8.5﹣3.9×8.5(2.55+9.6÷16)÷0.429.2÷0.25÷48.脱式计算(能简算的要简算)0.75×4×0.25×49.6+9.9×9915.58÷8.2﹣0.724.536÷0.8÷14 2.8×3.6+1.4×2.8 6.3×10.1.9.脱式计算(能简算的要用简算)4.2×7.8+2.2×4.2 9.5×101(8×3.82)×1.250.125×720.6×3.9×0.8 42×0.39+4.2×6.110.脱式计算,能简算的要简算0.25×1.25×1618.9﹣18.9÷1.48.37×1.2﹣8.37×0.243×11.8+5.7×118.11.用简便方法计算.6.2+5.18+2.8 15.35﹣(5.35+7.2)3.63﹣1.25+17.37﹣8.75 51.72﹣8.66﹣1.34.12.脱式计算,能简算的要简算.0.7×101﹣0.7 0.125×4.95×8 12.9﹣1.68﹣2.32 567÷20÷5.13.用递等式计算,能简算的要简算.20.16÷7.2+9.8 6.2×2.7+6.5×7.3 32.8+9.6+7.2.14.脱式计算:能简算的要简算15.89﹣(5.89+6.98)0.25×13.7×0.432.7×28+7.3×2815×9.4﹣42 4.9+12.87﹣5.380.05×0.7×20×1.7.15.计算下面各题,能简算的要简算.5.04×28(15.4﹣7.8)×3.5 3.2×4.6+3.2×5.40.25×17.4×4 20﹣6.72﹣3.28 8.33+7.45+1.67+2.5516.脱式计算.0.2×0.6×0.5×4 (7.5﹣2.3×0.4)÷0.011.2×0.25+2.8×0.25 178.8÷(26.4﹣5.6)17.能简算的要简算3.6﹣1.28+3.09 3.82+2.9+0.18+9.1 9.43﹣(6.28﹣1.57)21.32﹣(6.32+8.3)13.75﹣(3.75+6.48)15﹣7.35﹣2.6518.混合运算,能简便就简便19.81﹣2.68﹣8.32 5.6+6.6﹣5.6+6.60.81×27+0.19×27101×0.19﹣0.19.19.用简便方法计算9.08﹣1.76﹣4.24 18.38﹣(5.38+1.8)﹣8.217.45﹣(8.76﹣6.55)12.87+3.98﹣3.87.20.脱式计算,能简便的用简便方法计算.10.8÷(3.94+6.86)×0.80.65×201 12.5×3.9×0.839.8×0.25×4 37.6×8+37.6×20.78×99+0.78.21.脱式计算:21.8﹣7.22﹣2.789﹣0.24÷1.6×1.19.12+9.12×9﹣6.0245.2×66.7+66.7×53.8+66.70.25×0.8×0.125×0.412.75÷[14.6﹣(1.3+8.2)] 0.125×36×(4÷0.5)÷36[(6.1﹣4.6)×0.8﹣1]×0.3615.6﹣(4.1+0.2+6.86÷0.7)[5﹣(1﹣1.2×0.8)]÷41÷0.25+0.4×0.613.6×3﹣40.6÷225.8+10.5÷(5﹣3.5) 1.42﹣0.36÷6×0.649.5×0.2﹣2.07÷236.7+3.3÷4.4+5.622.计算下面各题(能简算的要简算)50×(0.8+0.4)7.34×2.1+7.34×6.8+7.34×1.120.5÷1.25÷0.8 9.88×9+9.88.23.计算下列各题(能用简便算法的要用简便算法).12.6÷(1.02+3.18) 5.7×6.9+4.3×6.9(0.81+2.7)÷0.9[(8.4﹣7.9)÷0.25]×1.2.25.能简算的用简便方法计算.(写出主要简便过程,无过程不得分)1.6×3.9×1.25 4.87×2.34+48.7×0.2660.49×9.9 0.05×0.7×20×1.72.5×3.2×12.5 3.95×7.6+3.95×3.4﹣3.95.26.计算下面各题,能简算的要简算7.8×6.9+2.2×6.9 2.36×2.5×4102×0.454.19×99+4.1921.36÷0.8﹣12.9 3.2÷0.8×0.2627.计算(能简算的要简算).6.33×101﹣6.33 1.6×55.4﹣55.4×0.617.68÷5.2+2.7×1.5(1.1﹣0.78)×(2.7﹣1.95)35.6﹣5×1.7315÷0.2÷2.528.脱式计算(能简算的要简算)2.5×1.37×0.4 4.8×0.25×250.89×4.8+0.89×5.2101×0.78×208.8×1.25×15 4.3×0.8×529.计算下面各题,能简算的要简算.44.28÷0.9÷4.10.25×0.39×47.6+7.6×999.07﹣22.78÷3.4 4.8×99+4.8 6.3×10.130.下面各题,能简算的就要简算.5.8+3.8×0.25 1.7×(4.65﹣3.87) 1.25×4.3×0.84.5×1020.54×101﹣0.54 3.4×2.5+6.6×2.5.31.计算下列各题.0.45×12×0.2 6.2×2.1﹣2.1 0.9×0.8×1002.8﹣2.8×0.15 2.8×1.43+0.57 72×0.81+10.310﹣6.06+8.56×0.25×1.8 7.06×2.4﹣5.832.用简便方法计算.0.25×9.87×4 36.2×1.8+13.8×1.8 0.125×2.3×80.73×102 (6.8+2.6)×5 0.23×98.33.能用简便方法的用简便方法计算12.5×32×2.5 6.8×9.9 7.2÷[1.8×(3.4﹣2.9)].34.用你喜欢的方法计算.3.4×9+3.4 6.4÷0.8﹣1.5×4 3.78÷0.25÷4 17÷[(1.2+0.5)×5].35.用你喜欢的方法计算2.5×1.25×8×0.4 12.8×1.7+87.2×1.7 100﹣4.35﹣5.65.36.用递等式计算(能简算的要简算).4+7.6×15 26.08÷0.25÷419.7+(80.5÷35×0.2)37.计算,能简算的要简算.1.25×2.25×0.8 9.7×99+9.7 4.8×7.8+78×0.523.65×10.1.38.计算下面各题.(能简算的用简便算法)①12.36﹣6.49﹣3.51②8.5×3.8+8.5×6.2③17.3×0.25×8④15.32﹣1.8×5﹣3.46⑤199×2.6⑥3.6÷[(1.3+0.6)×5] 39.计算8.5+6.85﹣6.35 3.9+0.1﹣3.9+0.1 12.6﹣(3.75+5.08)40.计算,能简算的要简算6.09﹣9.13÷8.3 3.84×9.6+0.96×61.6 4.86×995.68×4+4.32÷0.256.4×4.5+3.6×4.5.41.脱式计算.10.5+61×18 (3.14+12.6)÷8 4.5÷(15÷3)75+448÷4×19.42.计算:(18.5×3.8+3.8×2.5)÷0.19 [32﹣(7.25+0.75×8)]÷50.43.脱式计算,能简算的就简算:25.32﹣(3.4﹣1.2)12﹣0.62﹣4.38.44.用简便方法计算下面各题.5.12+2.54+4.8812.5×17.8×0.8 0.24×0.48×49.9×2.59.4×5.8+10.6×5.8 0.66×101 4.8×0.25 2.33×0.5×41.3×2.5+0.7×2.5 1.26×0.6+1.26×0.4 102×0.55 0.034×0.5×0.245.计算.(怎样简便就怎么计算)13.38+0.98=7.02﹣2.98 6.57﹣(0.68﹣0.39+0.32)13.8÷(1.38×0.2)30.7﹣0.12×2﹣0.76 7.8×1.0118.4﹣6.5+1.6+3.5 7.8÷0.6+7.8÷0.412.13+7.5﹣1.13+2.850.125×8.89.4×3.2+6×0.32 9.6×3.6+7.2×0.2.46.计算下面各题,能简算得要简算.96÷(100×0.48) 3.6÷(1.2+0.5)×6(967﹣31)÷(17+48)72×10.1+27×10.1.47.用自己喜欢的方法计算.3.4×7.8÷3.9 54÷(6.86+3.94)48.用简便方法计算0.486+0.01+3.99 17.5×2.3﹣7.5×2.3 1.25×11×4×0.8 4.8×39+61×4.8 45.55﹣(6.82+15.55) 3.2×99+3.22.5×56+4.5×56 (31.6﹣11.7)÷2.5÷43.6×0.9+3.6×0.149.计算下列各题.(能简算的要简算)7.5﹣2.4÷0.8×2.5 12.5×17+83×12.5399×2.5 25÷(2.5÷0.4)3.25×67+5.75×67+67 230÷2.5×7.5 6.3+0.84+3.7+8.16 100﹣(2.72+10.8)÷0.250.脱式计算0.25×3.25×4 6.72+3.2÷2.521.36÷0.4﹣23.40.8×4.5+1.2×4.5.小数除法脱式运算+简算260道参考答案与试题解析一.计算题(共50小题)1.【解答】解:(1)32×12.5×0.25=4×8×12.5×0.25=(4×0.25)×(8×12.5)=1×100=100(2)6.1×4.2+5.8×6.1=6.1×(4.2+5.8)=6.1×10=61(3)1.7÷2.5÷0.4=1.7÷(2.5×0.4)=1.7÷1=1.7(4)16.1﹣4.2﹣5.8=16.1﹣(4.2+5.8)=16.1﹣10=6.12.【解答】解:(1)(0.6×0.8+0.12)÷1.2=0.6÷1.2=0.5答:商是0.5.(2)(14.81+5.19)×(14.81﹣5.19)=20×9.62=192.4答:积是192.4.(3)[(2.7+4.5)÷12]×0.3=[7.2÷12]×0.3=0.6×0.3=0.18答:积是0.18.3.【解答】解:①4.8÷(1.2÷0.5)=4.8÷2.4=2②12.8﹣12.8÷5=12.8﹣2.56=10.24③71.4÷(7×6)=71.4÷7÷6=10.2÷6=1.74.【解答】解:①0.65×101﹣0.65 =0.65×(101﹣1)=0.65×100=65②12.6﹣3.25+6.75=12.6+(6.75﹣3.25)=12.6+3.5=16.1③6.35÷0.2÷0.5=6.35÷(0.2×0.5)=6.35÷0.1=63.5④5.7×1.2÷19 =5.7÷19×1.2=0.3×1.2=0.36⑤1.25×3.63×0.8=(1.25×0.8)×3.63=1×3.63=3.635.【解答】解:①0.11×1.8+8.2×0.11=0.11×(1.8+8.2)=0.11×10=1.1②3.5﹣3.5×0.98=3.5×(1﹣0.98)=3.5×0.02=0.07③0.75×18÷0.15=0.75÷0.15×18=5×18=90④0.25×4.78×8=0.25×8×4.78=2×4.78=9.566.【解答】解:①17.3÷0.125÷8 =17.3÷(0.125×8)=17.3÷1=17.3 ②14.72×0.7+5.28×0.7=(14.72+5.28)×0.7=20×0.7=14③3.5÷0.56 =(3.5÷0.7)÷(0.56÷0.7)=5÷8=0.625④8.5×9.9+0.82=8.5×(10﹣0.1)+0.82=8.5×10﹣8.5×0.1+0.82=85﹣0.85+0.82=85﹣(0.85﹣0.82)=85﹣0.03=84.977.【解答】解:(1)38.75﹣(24.5+8.75)=38.75﹣24.5﹣8.75=38.75﹣8.75﹣24.5=30﹣24.5=5.5;(2)0.4×2.32×0.25=0.4×0.25×2.32=0.1×2.32=0.232;(3)0.75×101=0.75×(100+1)=0.75×100+0.75×1=75+0.75=75.75;(4)4.2﹣3.2×0.9=4.2﹣2.88=1.32;(5)7.56×99+7.56=7.56×(99+1)=7.56×100=756;(6)70.3﹣17.48÷7.6=70.3﹣2.3=68;(7)3.64÷5.2×23.3=0.7×23.3=16.31;(8)21.8÷0.8﹣1.2×5=27.25﹣6=21.25;(9)45÷(5.25÷0.25)=45÷21=;(10)16.5×101﹣16.5=16.5×(101﹣1)=16.5×100=1650;(11)0.96÷0.3×14=3.2×14=44.8;(12)1.25×4×2.5×8=(1.25×8)×(4×2.5)=10×10=100;(13)36.45÷(0.82+3.4×0.2)=36.45÷(0.82+0.68)=36.45÷1.5=24.3;(14)9.07﹣2.64÷0.4=9.07﹣6.6=2.47;(15)1.5×101=1.5×(100+1)=1.5×100+1.5×1=150+1.5=151.5;(16)12.6×7.5+8.3=94.5+8.3=102.8;(17)13.6×0.85﹣3.6×0.85=(13.6﹣3.6)×0.85=10×0.85=8.5;(18)104×8.5=(100+4)×8.5=100×8.5+4×8.5=850+34=884;(19)86.4÷6.4﹣0.4=13.5﹣0.4=13.1;(20)0.25×6.2×0.4=0.25×0.4×6.2=0.1×6.2=0.62;(21)23×6.5+17×6.5=(23+17)×6.5=40×6.5=260;(22)36÷0.4×0.25=90×0.25=22.5;(23)(24.6﹣18.1)×3.4=6.5×3.4=22.1;(24)7.6×9.9+7.6×0.1=7.6×(9.9+0.1)=7.6×10=76;(25)13.6×0.8×12.5=13.6×(0.8×12.5)=13.6×10=136;(26)23.9×8.5﹣3.9×8.5=(23.9﹣3.9)×8.5=20×8.5=170;(27)(2.55+9.6÷16)÷0.42=(2.55+0.6)÷0.42=3.15÷0.42=7.5;(28)9.2÷0.25÷4=9.2÷(0.25×4)=9.2÷1=9.2.8.【解答】解:(1)0.75×4×0.25×4=(0.75×4)×(0.25×4)=3×1=3(2)9.6+9.9×99=9.6+9.9×(100﹣1)=9.6+9.9×100﹣9.9=9.6+990﹣9.9=989.7(3)15.58÷8.2﹣0.72=1.9﹣0.72=1.18(4)4.536÷0.8÷14=5.67÷14=0.405(5)2.8×3.6+1.4×2.8=2.8×(3.6+1.4)=2.8×5=14(6)6.3×10.1=6.3×(10+0.1)=6.3×10+6.3×0.1=63+0.63=63.639.【解答】解:(1)4.2×7.8+2.2×4.2 =4.2×(7.8+2.2 )=4.2×10=42(2)9.5×101=9.5×(100+1)=9.5×100+9.5=950+9.5=959.5(3)(8×3.82)×1.25 =(8×1.25)×3.82=10×3.82=38.2(4)0.125×72=0.125×8×9=1×9=9(5)0.6×3.9×0.8 =2.34×0.8=1.872(6)42×0.39+4.2×6.1=42×0.39+42×0.61=42×(0.39+0.61)=42×1=42 10.【解答】解:(1)0.25×1.25×16=0.25×1.25×(2×8)=(0.25×2)×(1.25×8)=0.5×10=5(2)18.9﹣18.9÷1.4=18.9﹣13.5=5.4(3)8.37×1.2﹣8.37×0.2=8.37×(1.2﹣0.2)=8.37×1=8.37(4)43×11.8+5.7×118=43×11.8+57×11.8=(43+57)×11.8=100×11.8=118011.【解答】解:(1)6.2+5.18+2.8 =6.2+2.8+5.18 =9+5.18=14.18 (2)15.35﹣(5.35+7.2)=15.35﹣5.35﹣7.2=10﹣7.2=2.8(3)3.63﹣1.25+17.37﹣8.75=(3.63+17.37)﹣(1.25+8.75)=21﹣10=11 (4)51.72﹣8.66﹣1.34=51.72﹣(8.66+1.34)=51.72﹣10=41.7212.【解答】解:(1)0.7×101﹣0.7 =0.7×(101﹣1)=0.7×100=70(2)0.125×4.7×8=0.125×8×4.7=1×4.7=4.7(3)12.9﹣1.68﹣2.32 =12.9﹣(1.68+2.32)=12.9﹣4=8.9(4)567÷20÷5=567÷(20×5)=567÷100=5.6713.【解答】解:①20.16÷7.2+9.8 =2.8+9.8=12.6;②6.2×2.7+6.5×7.3 =16.74+47.45=64.19;③32.8+9.6+7.2=9.6+(32.8+7.2)=9.6+40=49.6.14.【解答】解:(1)15.89﹣(5.89+6.98)=15.89﹣5.89﹣6.98=10﹣6.98=3.02;(2)0.25×13.7×0.4=0.25×0.4×13.7=0.1×13.7=1.37;(3)32.7×28+7.3×28 =(32.7+7.3)×28=40×28=1120;(4)15×9.4﹣42=141﹣42=99;(5)4.9+12.87﹣5.38=17.77﹣5.38=12.39;(6)0.05×0.7×20×1.7=0.05×20×0.7×1.7=1×0.7×1.7=0.7×1.7=1.19.15.【解答】解:(1)5.04×28=(5+0.04)×28=5×28+0.04×28=140+1.12=141.12;(2)(15.4﹣7.8)×3.5 =7.6×3.5 =26.6;(3)3.2×4.6+3.2×5.4=3.2×(4.6+5.4)=3.2×10=32;(4)0.25×17.4×4=0.25×4×17.4=1×17.4=17.4;(5)20﹣6.72﹣3.28=20﹣(6.72+3.28)=20﹣10=10;(6)8.33+7.45+1.67+2.55=8.33+1.67+7.45+2.55=(8.33+1.67)+(7.45+2.55)=10+10=20.16.【解答】解:(1)0.2×0.6×0.5×4 =(0.2×0.5)×(0.6×4)=0.1×2.4=0.24;(2)(7.5﹣2.3×0.4)÷0.01=(7.5﹣0.92)÷0.01=6.58÷0.01=658;(3)1.2×0.25+2.8×0.25 =(1.2+2.8)×0.25=4×0.25=1;(4)178.8÷(26.4﹣5.6)=178.8÷20.8=.17.【解答】解:(1)3.6﹣1.28+3.09=2.32+3.09=5.41(2)3.82+2.9+0.18+9.1 =(3.82+0.18)+(9.1+2.9)=4+12=16(3)9.43﹣(6.28﹣1.57)=9.43+1.57﹣6.28=11﹣6.28=4.72(4)21.32﹣(6.32+8.3)=21.32﹣6.32﹣8.3=15﹣8.3=6.7(5)13.75﹣(3.75+6.48)=13.75﹣3.75﹣6.48=10﹣6.48=3.52(6)15﹣7.35﹣2.65=15﹣(7.35+2.65)=15﹣10=518.【解答】解:①19.81﹣2.68﹣8.32=19.81﹣(2.68+8.32)=19.81﹣11=8.81②5.6+6.6﹣5.6+6.6=(5.6﹣5.6)+(6.6+6.6)=0+13.2=13.2③0.81×27+0.19×27=27×(0.81+0.19)=27×1=27④101×0.19﹣0.19=(101﹣1)×0.19=100×0.19=1919.【解答】解:(1)9.08﹣1.76﹣ 4.24 =9.08﹣(1.76+4.24)=9.08﹣6=3.08;(2)18.38﹣(5.38+1.8)﹣8.2=18.38﹣7.18﹣8.2=11.2﹣8.2=3;(3)17.45﹣(8.76﹣6.55)=17.45﹣8.76+6.55=17.45+6.55﹣8.76=24﹣8.76=15.24;(4)12.87+3.98﹣3.87=12.87﹣3.87+3.98=9+3.98=12.98.20.【解答】解:①10.8÷(3.94+6.86)×0.8=10.8÷10.8×0.8=1×0.8=0.8②0.65×201 =0.65×(200+1)=0.65×200+0.65×1=130+0.65=130.65③12.5×3.9×0.8=12.5×0.8×3.9=10×3.9=39④39.8×0.25×4 =39.8×(0.25×4)=39.8×1=39.8⑤37.6×8+37.6×2=37.6×(8+2)=37.6×10=376⑥0.78×99+0.78=0.78×(99+1)=0.78×100=78 21.【解答】解:(1)21.8﹣7.22﹣2.78=21.8﹣(7.22+2.78)=21.8﹣10=11.8(2)9﹣0.24÷1.6×1.1=9﹣0.15×1.1=9﹣0.165=8.835(3)9.12+9.12×9﹣6.02=9.12×(1+9)﹣6.02=9.12×10﹣6.02=91.2﹣6.02=85.18(4)45.2×66.7+66.7×53.8+66.7=(45.2+53.8+1)×66.7=100×66.7=6670(5)0.25×0.8×0.125×0.4=(0.25×0.4)×(0.125×0.8)=0.1×0.1=0.01(6)12.75÷[14.6﹣(1.3+8.2)]=12.75÷[14.6﹣9.5]=12.75÷5.1=2.5(7)0.125×36×(4÷0.5)÷36=0.125×(4÷0.5)×(36÷36)=0.125×8×1=1(8)[(6.1﹣4.6)×0.8﹣1]×0.36=[1.5×0.8﹣1]×0.36=[1.2﹣1]×0.36=0.2×0.36=0.072(9)15.6﹣(4.1+0.2+6.86÷0.7)=15.6﹣(4.1+0.2+9.8)=15.5﹣(4.1+10)=15.5﹣14.1=1.4(10)[5﹣(1﹣1.2×0.8)]÷4=[5﹣(1﹣0.96)]÷4=[5﹣0.04]÷4=4.96÷4=1.24(11)1÷0.25+0.4×0.6=4+0.24=4.24(12)13.6×3﹣40.6÷2=40.8﹣20.3=20.5(13)25.8+10.5÷(5﹣3.5)=25.8+10.5÷1.5=25.8+7=32.8(14)1.42﹣0.36÷6×0.6=1.42﹣0.36=1.07(15)49.5×0.2﹣ 2.07÷23=9.9﹣0.09=9.81(16) 6.7+3.3÷4.4+5.6=6.7+0.75+5.6=7.45+5.6=13.0522.【解答】解:①50×(0.8+0.4)=50×0.8+50×0.4=40+20=60②7.34×2.1+7.34×6.8+7.34×1.1=7.34×(2.1+6.8+1.1)=7.34×10=73.4③20.5÷1.25÷0.8=20.5÷(1.25×0.8)=20.5÷1=20.5 ④9.88×9+9.88=9.88×(9+1)=9.88×10=98.823.【解答】解:(1)12.6÷(1.02+3.18)=12.6÷4.2=3;(2)5.7×6.9+4.3×6.9=(5.7+4.3)×6.9=10×6.9=69;(3)(0.81+2.7)÷0.9=3.51÷0.9=3.9;(4)[(8.4﹣7.9)÷0.25]×1.2=[0.5÷0.25]×1.2=2×1.2=2.4.24.【解答】解:(1)25×1.25×32 =25×1.25×8×4=(25×4)×(1.25×8)=100×10=1000(2)(+)×35=×35+×35=10+7=17(3)78×=(79﹣1)×=79×﹣=3﹣=2(4)÷+=÷=25.【解答】解:(1)1.6×3.9×1.25=0.8×2×3.9×1.25=(0.8×1.25)×(2×3.9)=1×7.8=7.8(2)4.87×2.34+48.7×0.266=4.87×2.34+4.87×2.66=4.87×(2.34+2.66)=4.87×5=24.35(3)0.49×9.9 =0.49×(10﹣0.1)=0.49×10﹣0.49×0.1=4.9﹣0.049=4.851(4)0.05×0.7×20×1.7=(0.05×20)×(0.7×1.7)=1×1.19=1.19(5)2.5×3.2×12.5 =2.5×0.4×8×12.5 =(2.5×0.4)×(8×12.5)=1×100=100(6)3.95×7.6+3.95×3.4﹣3.95=3.95×(7.6+3.4﹣1)=3.95×10=39.5 26.【解答】解:(1)7.8×6.9+2.2×6.9=(7.8+2.2)×6.9=10×6.9=69(2)2.36×2.5×4=2.36×(2.5×4)=2.36×10=23.6(3)102×0.45=(100+2)×0.45=100×0.45+2×0.45=45+0.9=45.9(4)4.19×99+4.19=4.19×(99+1)=4.19×100=419(5)21.36÷0.8﹣12.9=26.7﹣12.9=13.8(6)3.2÷0.8×0.26=4×0.26=1.0427.【解答】解:(1)6.33×101﹣6.33=6.33×(101﹣1)=6.33×100=633;(2)1.6×55.4﹣55.4×0.6=(1.6﹣0.6)×55.4=1×55.4=55.4;(3)17.68÷5.2+2.7×1.5=3.4+4.05=7.45;(4)(1.1﹣0.78)×(2.7﹣1.95)=0.32×0.75=0.24;(5)35.6﹣5×1.73=35.6﹣8.65=26.95;(6)15÷0.2÷2.5=15÷(0.2×2.5)=15÷0.5=30.28.【解答】解:(1)2.5×1.37×0.4=2.5×0.4×1.37=1×1.37=1.37;(2)4.8×0.25×25=(4×4×0.3)×0.25×25=(4×0.25)×(4×25)×0.3=1×100×0.3=30;(3)0.89×4.8+0.89×5.2=0.89×(4.8+5.2)=0.89×10=8.9;(4)101×0.78×20=101×(0.78×20)=101×15.6=(100+1)×15.6=100×15.6+1×15.6=1560+15.6=1575.6;(5)8.8×1.25×15=(8×1.1)×1.25×15=(8×1.25)×(1.1×15)=10×16.5=165;(6)4.3×0.8×5=4.3×(0.8×5)=4.3×4=17.2.29.【解答】解:(1)44.28÷0.9÷4.1=49.2÷4.1=12;(2)0.25×0.39×4=(0.25×4)×0.39=1×0.39=0.39;(3)7.6+7.6×99=7.6×(1+99)=7.6×100=760;(4)9.07﹣22.78÷3.4=9.07﹣6.7=2.37;(5)4.8×99+4.8=4.8×(99+1)=4.8×100=480;(6)6.3×10.1=6.3×(10+0.1)=6.3×10+6.3×0.1=63+0.63=63.63.30.【解答】解:(1)5.8+3.8×0.25=5.8+0.95=6.75(2)1.7×(4.65﹣3.87)=1.7×0.78=1.326(3)1.25×4.3×0.8=1.25×0.8×4.3=1×4.3=4.3(4)4.5×102=4.5×(100+2)=4.5×100+4.5×2=450+9=459(5)0.54×101﹣0.54=0.54×(101﹣1)=0.54×100=54(6)3.4×2.5+6.6×2.5=(3.4+6.6)×2.5=10×2.5=2531.【解答】解:①0.45×12×0.2=0.45×0.2×12=0.09×12=1.08②6.2×2.1﹣2.1 =2.1×(6.2﹣1)=2.1×5.2=10.92 ③0.9×0.8×100=0.72×100=72④2.8﹣2.8×0.15 =2.8×(1﹣0.15)=2.8×0.85=2.38 ⑤2.8×1.43+0.57 =4.004+0.57=4.574⑥72×0.81+10.3=58.32+10.3=68.62⑦10﹣6.06+8.5=3.94+8.5=12.44⑧6×0.25×1.8 =1.5×1.8=2.7⑨7.06×2.4﹣5.8 =16.944﹣5.8=11.14432.【解答】解:(1)0.25×9.87×4 =0.25×4×9.87=1×9.87=9.87;(2)36.2×1.8+13.8×1.8 =(36.2+13.8)×1.8=50×1.8=90;(3)0.125×2.3×8=0.125×8×2.3=1×2.3=2.3;(4)0.73×102 =0.73×(100+2)=0.73×100+0.73×2=73+1.46=74.46;(5)(6.8+2.6)×5 =6.8×5+2.6×5=34+13=47;(6)0.23×98=0.23×(100﹣2)=0.23×100﹣0.23×2=23﹣0.46=22.54.33.【解答】解:(1)12.5×32×2.5 =12.5×4×8×2.5=(12.5×8)×(2.5×4)=100×10=1000;(2)6.8×9.9 =6.8×(10﹣0.1)=6.8×10﹣6.8×0.1=68﹣0.68=67.32;(3)7.2÷[1.8×(3.4﹣2.9)]=7.2÷[1.8×0.5]=7.2÷0.9=8.34.【解答】解:(1)3.4×9+3.4=30.6+3.4=34;(2)6.4÷0.8﹣1.5×4=8﹣6=2;(3)3.78÷0.25÷4=3.78÷(0.25×4)=3.78÷1=3.78;(4)17÷[(1.2+0.5)×5]=17÷[1.7×5]=17÷8.5=2.35.【解答】解:(1)2.5×1.25×8×0.4 =(2.5×0.4)×(1.25×8)=1×10=10;(2)12.8×1.7+87.2×1.7 =(12.8+87.2)×1.7=100×1.7=170;(3)100﹣4.35﹣5.65=100﹣(4.35+5.65)=100﹣10=90.36.【解答】解:(1)4+7.6×15 =4+114=118;(2)26.08÷0.25÷4=26.08÷(0.25×4)=26.08÷1=26.08;(3)19.7+(80.5÷35×0.2)=19.7+(2.3×0.2)=19.7+0.46=20.16.37.【解答】解:(1)1.25×2.25×0.8=1.25×0.8×2.25=1×2.25=2.25;(2)9.7×99+9.7=9.7×(99+1)=9.7×100=970;(3)4.8×7.8+78×0.52=4.8×7.8+7.8×5.2=(4.8+5.2)×7.8=10×7.8=78;(4)3.65×10.1=3.65×(10+0.1)=3.65×10+3.65×0.1=36.5+0.365=36.865.38.【解答】解:①12.36﹣6.49﹣3.51=12.36﹣(6.49+3.51)=12.36﹣10=2.36;②8.5×3.8+8.5×6.2=8.5×(3.8+6.2)=8.5×10=85;③17.3×0.25×8=17.3×(0.25×8)=17.3×2=34.6;④15.32﹣1.8×5﹣3.46=15.32﹣9﹣3.46=6.32﹣3.46=2.86;⑤199×2.6=(200﹣1)×2.6=200×2.6﹣1×2.6=520﹣2.6=517.4;⑥3.6÷[(1.3+0.6)×5]=3.6÷[1.9×5]=3.6÷9.5=.39.【解答】解:(1)8.5+6.85﹣6.35 =8.5+(6.85﹣6.35)=8.5+0.5=9;(2)3.9+0.1﹣3.9+0.1 =(3.9﹣3.9)+(0.1+0.1)=0+0.2=0.2;(3)12.6﹣(3.75+5.08)=12.6﹣8.83=3.77.40.【解答】解:(1)6.09﹣9.13÷8.3=6.09﹣1.1=4.99(2)3.84×9.6+0.96×61.6 =(3.84+6.16)×9.6=10×9.6=96(3)4.86×99=4.86×(100﹣1)=4.86×100﹣4.86=486﹣4.86=481.14(4)5.68×4+4.32÷0.25 =5.68×4+4.32×4=(5.68+4.32)×4=10×4=40(5)6.4×4.5+3.6×4.5=(6.4+3.6)×4.5=10×4.5=4541.【解答】解:①10.5+61×18=10.5+1098=1108.5 ②(3.14+12.6)÷8=15.74÷8=1.9675③4.5÷(15÷3)=4.5÷5=0.9④75+448÷4×19=75+112×19=75+2128=220342.【解答】解:(1)(18.5×3.8+3.8×2.5)÷0.19 =3.8×(18.5+2.5)÷0.19 =3.8×21÷0.19=3.8÷0.19×21=200×21=4200(2)[32﹣(7.25+0.75×8)]÷50=[32﹣(7.25+6)]÷50=[32﹣13.25]÷50=18.75÷50=0.37543.【解答】解:①25.32﹣(3.4﹣1.2)=25.32﹣2.2=23.12②12﹣0.62﹣4.38=12﹣(0.62+4.38)=12﹣5=7 44.【解答】解:(1)5.12+2.54+4.88=5.12+4.88+2.54=10+2.54=12.54;(2)12.5×17.8×0.8=12.5×0.8×17.8=10×17.8=178;(3)0.24×0.48×4=0.1152×4=0.4608;(4)9.9×2.5=(10﹣0.1)×2.5=10×2.5﹣0.1×2.5=25﹣0.25=24.75;(5)9.4×5.8+10.6×5.8=(9.4+10.6)×5.8=20×5.8=116;(6)0.66×101=0.66×(100+1)=0.66×100+0.66×1=66+0.66=66.66;(7)4.8×0.25=(1.2×4)×0.25=1.2×(4×0.25)=1.2×1=1.2;(8)2.33×0.5×4 =2.33×(0.5×4)=2.33×2=4.66;(9)1.3×2.5+0.7×2.5=(1.3+0.7)×2.5=2×2.5=5;(10)1.26×0.6+1.26×0.4=1.26×(0.6+0.4)=1.26×1=1.26;(11)102×0.55=(100+2)×0.55=100×0.55+2×0.55=55+1.1=56.1;(12)0.034×0.5×0.2=0.034×(0.5×0.2)=0.034×0.1=0.0034.45.【解答】解:(1)13.38+0.98=13.38+(1﹣0.02)=13.38+1﹣0.02=14.38﹣0.02=14.36;(2)7.02﹣2.98 =7.02﹣(3﹣0.02)=7.02﹣3+0.02 =4.02+0.02=4.04;(3)6.57﹣(0.68﹣0.39+0.32)=6.57﹣(0.68+0.32﹣0.39)=6.57﹣(1﹣0.39)=6.57﹣0.61=5.96;(4)13.8÷(1.38×0.2)=13.8÷1.38÷0.2=10÷0.2=50;(5)30.7﹣0.12×2﹣0.76 =30.7﹣0.24﹣0.76=30.7﹣(0.24+0.76)=30.7﹣1=29.7;(6)7.8×1.01=7.8×(1+0.01)=7.8×1+7.8×0.01=7.8+0.078=7.878;(7)18.4﹣6.5+1.6+3.5 =(18.4+1.6)﹣(6.5﹣3.5)=20﹣3=17;(8)7.8÷0.6+7.8÷0.4=13+19.5=32.5;(9)12.13+7.5﹣1.13+2.85=(12.13﹣1.13)+(7.5+2.85)=11﹣10.35=0.65;(10)0.125×8.8=0.125×(8+0.8)=0.125×8+0.125×0.8=1+0.1=1.1;(11)9.4×3.2+6×0.32 =9.4×3.2+0.6×3.2=(9.4+0.6)×3.2=10×3.2=32;(12)9.6×3.6+7.2×0.2=9.6×3.6+3.6×2×0.2=9.6×3.6+3.6×0.4=(9.6+0.4)×3.6=10×3.6=36.46.【解答】解:(1)96÷(100×0.48)=96÷48=2;(2)3.6÷(1.2+0.5)×6=3.6÷1.7×6=×6=;(3)(967﹣31)÷(17+48)=936÷65=14.4;(4)72×10.1+27×10.1=(72+27)×10.1=99×10.1=99×(10+0.1)=99×10+99×0.1=990+9.9=999.9.47.【解答】解:(1)3.4×7.8÷3.9=26.52÷3.9=6.8;(2)54÷(3.94+6.86)=54÷10.8=5.48.【解答】解:①0.486+0.01+3.99 =0.486+(0.01+3.99)=0.486+4=4.486 ②17.5×2.3﹣7.5×2.3 =2.3×(17.5﹣7.5)=2.3×10=23 ③1.25×11×4×0.8=(1.25×0.8)×(11×4)=1×44=44④4.8×39+61×4.8=4.8×(39+61)=4.8×100=480 ⑤45.55﹣(6.82+15.55)=45.55﹣6.82﹣15.55=45.55﹣15.55﹣6.82=30﹣6.82=23.18⑥3.2×99+3.2=3.2×(99+1)=3.2×100=320⑦2.5×56+4.5×56 =56×(2.5+4.5)=56×7=392⑧(31.6﹣11.7)÷2.5÷4 =19.9÷(2.5×4)=19.9÷10=1.99⑨3.6×0.9+3.6×0.1=3.6×(0.9+0.1)=3.6×1=3.649.【解答】解:(1)7.5﹣2.4÷0.8×2.5 =7.5﹣3×2.5=7.5﹣7.5=0;(2)12.5×17+83×12.5=12.5×(17+83)=12.5×100=1250;(3)399×2.5 =(400﹣1)×2.5=400×2.5﹣2.5=1000﹣2.5=997.25;(4)25÷(2.5÷0.4)=25÷2.5×0.4=10×0.4=4;(5)3.25×67+5.75×67+67 =(3.25+5.75+1)×67=10×67=670;(6)230÷2.5×7.5=92×7.5=690;(7)6.3+0.84+3.7+8.16=(6.3+3.7)+(0.84+8.16)=10+9=19;(8)100﹣(2.72+10.8)÷0.2=100﹣13.52÷0.2=100﹣67.6=32.4.50.【解答】解:(1)0.25×3.25×4=0.25×4×3.25=1×3.25=3.25(2)6.72+3.2÷2.5=6.72+1.28=8(3)21.36÷0.4﹣23.4=53.4﹣23.4=30(4)0.8×4.5+1.2×4.5=(0.8+1.2)×4.5=2×4.5=9。

五年级题目2道小数乘法、2道小数除法、1道简算、2道解决问题

五年级题目2道小数乘法、2道小数除法、1道简算、2道解决问题

五年级题目2道小数乘法、2道小数除法、1道简算、2道解
决问题
这里是五年级的数学题目,包括2道小数乘法、2道小数除法、1道简算和2道解决问题。

1. 小数乘法:小明有 0.5 公斤的苹果,他要将它们分成 5 个袋子,每个袋子里放相同数量的苹果,请问每个袋子里应该放多少个苹果?
2. 小数乘法:一箱牛奶有 12 瓶,每瓶有 0.25 升,一共有多少升牛奶?
3. 小数除法:小明有 3.75 元钱,他想买一本书,这本书的价格是 0.25 元,他最多可以买几本这样的书?
4. 小数除法:一辆汽车每小时可以行驶 60 公里,它要行驶 450 公里,需要多少小时?
5. 简算:(25 + 13)x 2 - 25 = ?
6. 解决问题:小明家离学校有 3.5 公里,他走路的速度是每小时 5 公里,他几点出发才能在 7 点到达学校?
7. 解决问题:小华有 2.5 元钱,他想买 4 个小玩具和一袋糖果,每个小玩具的价格是 0.5 元,每袋糖果的价格是 0.75 元,他能买到吗?如果能,他还剩下多少钱?
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