小学五年级数学简便计算练习题及答案
五年级数学简便计算含解析答案
简便计算2练习题例1 ÷÷4解析:运用除法的性质:a÷b÷c=a÷b×c使计算简便;答案:÷÷4=÷×4=÷1=例2 ×98+解析:动态线条将分成×2答案:×98+=×98+×2=×98+2=×100=1560小结:小数的计算中,我们可以运用乘法分配律,进行简便计算;但是这一题我们一开始看不出相同的数,但是发现正好可以换成2个,即×2,下面再利用乘法分配律进行简便计算就可以了;例3×+×+×101解析:、、在×,变为×在×101,变为×答案:×+×+×101=×+×+×=×++=×100=435小结:这是一道多积求和的题目,在三个积里,我们可以运用积不变的规律使其统一,这样就可以顺利解决了;例4÷××26÷解析:÷和×26;×和÷改变运算顺序可以使计算简便;同时将×26挪到÷前面加两个括号答案:÷××26÷=×26÷×÷=×100×10=50300例5÷+÷+÷+÷解析:所有的÷几个除数都是,可以先把几个被除数相加,所得的和再除以即可;答案:÷+÷+÷+÷=+++÷=8÷=10。
新人教版小学数学五年级简便计算题及答案
五年级数学简便计算题及答案3.29+0.73+2.27 3.29-0.73-2.27 7.5+2.5-7.5+2.57.325-3.29-3.325 7.325-(5.325+1.7) 3.29+0.73-2.29+2.273.29×0.25×4 0.125×8.8 0.25×0.28 0.125×3.2×2.5 35×10.2 0.25×4÷0.25×4 3.5×101-3.5 3.5×9.9+3.5×0.1 3.5×2.7+35×0.733.5×2.7-3.5×0.7 (32+5.6)÷0.8 3.5÷0.6-0.5÷0.64.9÷1.4 7÷0.25÷4 7÷0.1257.35÷(7.35×0.25) 7.35÷(7.35÷0.25)3.07-0.38-1.62 1.29+3.7+2.71+6.38-2.45-1.55 3.25+1.79-0.59+1.7523.4-0.8-13.4-7.2 0.32×4033.2+0.36+4.8+1.64 1.23+3.4-0.23+6.6 0.25×3612.7-(3.7+0.84)36.54-1.76-4.54 0.25×0.73×4 7.6×0.8+0.2×7.6 0.85×199 0.25×8.5×41.28×8.6+0.72×8.6 12.5×0.96×0.8 10.4-9.6×0.350.8×(4.3×1.25) 3.12+3.12×99 28.6×101-28.6 (4.23+6.17)×0.8 0.86×15.7-0.86×14.7 2.4×102 14-7.32-2.68 2.64+8.67+7.36+11.33答案3.29+0.73+2.27 3.29-0.73-2.27 7.5+2.5-7.5+2.5=3.29+(0.73+2.27) =3.29-(0.73+2.27) =(7.5-7.5)+(2.5+2.5)=3.29+3 =3.29-3 =0+5=6.29 =0.29 =5(加法结合律)(减法的性质)(同级运算交换)7.325-3.29-3.325 7.325-(5.325+1.7)=7.325-3.325-3.29 =7.325-5.325-1.7=4-3.29 =2-1.7=0.71 =0.3(减法交换)(减法的性质)3.29+0.73-2.29+2.27 3.29×0.25×4 0.125×8.8=(3.29-2.29)+(0.73+2.27) =3.29×(0.25×4)=0.125×8×1.1=1+3 =3.29×1 =1×1.1=4 =3.29 =1.1(同级运算交换)(乘法结合律)(先拆数,乘法结合律)0.25×0.28 0.125×3.2×2.5 35×10.2=0.25×4×0.07 =(0.125×8)×(0.4×2.5)=35×(10+0.2)=1×0.07 =1×1 =35×10+35×0.2=0.07 =1 =350+7(先拆数,乘法结合律)(拆数,乘法结合律) =357(拆数,乘法分配律)0.25×4÷0.25×4=(0.25÷0.25)×(4×4)=1×16=16(同级运算交换)3.5×101-3.5 3.5×9.9+3.5×0.1 ★ 3.5×2.7+35×0.73=3.5×(101-1) =3.5×(9.9+0.1) =3.5×2.7+3.5×7.3=3.5×100 =3.5×10 =3.5×(2.7+7.3)=350 =35 =3.5×10(乘法分配律)(乘法分配律) =35(先利用积不变的规律转化,然后再用乘法分配律)3.5×2.7-3.5×0.7 ★ (32+5.6)÷0.8 ★ 3.5÷0.6-0.5÷0.6=3.5×(2.7-0.7) =32÷0.8+5.6÷0.8 =(3.5-0.5)÷0.6=3.5×2 =40+7 =3÷0.6=7 =47 =5(乘法分配律)(后2题类似分配律,但只适用于(a+b)÷c和(a-b)÷c,而a÷(b+c)和a÷(b-c)不能用。
五年级简便运算300题及答案
五年级简便运算300题及答案五年级上数学计算题大全300道五年级数学题上册竖式计算(一)2.5×103= 0.702×15=3.15×0.14= 12.4×0.17=2.3×11.2=0.416÷32= 6.6÷4= 43.5÷29= 28.6÷11= 20.4÷24=3.9×0.3=4.3×6.2= 3.64÷52= 15.6÷12= 328÷16=竖式计算(二)2.19÷0.3= 5.58÷3.1= 8.32÷4= 5.92÷1.6= 0.63÷0.15= 6.7×0.3= 0.68×0.04= 3.9×5.6= 0.285×7= 58×0.009= 6.15×0.4= 56×1.33= 140.4÷18= 9.18÷9= 243.2÷6.4=竖式计算(三)3.5×1.6= 12.5×40= 1.3×2.3= 3.02×2.05= 2.6×1.8=7÷0.28= 15.6÷2= 0.138÷0.15= 216÷2.7= 6.4÷32=1.37×0.04= 1.06×2.05= 104÷0.52= 72÷3.8= 75.6÷1.8=竖式计算(四)0.396÷1.2= 0.756÷0.36= 15.6×13= 0.18×15=0.025×14=3.06×36= 0.04×0.12= 3.84×2.6≈ 5.76×3= 7.15×22=90.75÷3.3 3.68×0.25= 16.9÷0.13= 1.55÷3.9=3.7×0.016=简便计算(一)66.86-8.66-1.34 0.25×16.2×4 0.25×16.2×4 4.8×7.8+78×0.523.6×1024.8×100.1 56.5×9.9+56.5 7.09×10.8-0.8×7.094.2÷3.5 320÷1.25÷8 18.76×9.9+18.76 3.52÷2.5÷0.4简便计算(二)1.25×2.5×32 0.49÷1.43.65×10.1 15.2÷0.25÷415.6×13.1-15.6-15.6×2.1 4.2×99+4.2 0.89×100.1 17.8÷(1.78×4)(45.9-32.7)÷8÷0.125 9.7×99+9.7 4.36×12.5×85.6÷3.5简便计算(三)0.65×101 27.5×3.7-7.5×3.7 8.54÷2.5÷0.43.83×4.56+3.83×5.4445×(267+143) 2.5×0.39×0.4 (25+2.5+0.25)×41.8×3.5+2.5×1.812.5×8.8 3.6×1.2÷3.6×1.2 1.31×12.5×8×23.8×0.99简便计算(四)4.6×99+4.6 7.5×101-7.5 1.25×2.5×(80×4)4.6×47+4.6×54-4.67.68÷2.5÷0.4 0.45×72+45×0.18+4.5 5.5×99 0.125×7212.5×0.4×2.5×8 9.5×101 4.2×7.8+2.2×4.20.87×3.36+4.64×0.87解方程(一)20X-50=50 28+6X=88 32-22X=10 3X+5X=483X-24-=3 1.8x=0.972 X+3=18 X-6=1214X-8X=12 12X-8X=4.8 7.5×2X=15 4(X-5.6)=1.6解方程(二)7x =49 20x=40 8x=8 1.2x=81.6x+3=18 x+32=76 100+x=310 x+55=129x-54.3=100 x-77=275 x-58=144 11.6-x=8x÷2.5=100 x÷3=33.3 x÷2.2=8 6÷x=12解方程(三)0.273÷x=0.35 1.8x=0.972 5x+34=54 2(x+x+0.5)=9.85(x+3)=35 x+3.7x+2=16.1 3x-1.2x=158 2x+55=1293×(x-4)=46 (8+x)÷5=15 (x+5) ÷3=16 6×5+2x=44解方程(四)20X-50=50 28+6X=88 32-22X=10 56-2X=204X+2=6 3X+6=18 16+8X=40 2X-8=84X-3×9=29 7(X-2)=49 4×8+2X=36 48-27+5X=31数学五年级上计算训练(一)1、直接写出得数。
小学数学五年级简便计算题及答案
五年级数学简便计算题及答案3.29+0.73+2.27 3.29-0.73-2.27 7.5+2.5-7.5+2.57.325-3.29-3.325 7.325-(5.325+1.7) 3.29+0.73-2.29+2.273.29×0.25×40.125×8.80.25×0.280.125×3.2×2.535×10.20.25×4÷0.25×43.5×101-3.5 3.5×9.9+3.5×0.1 3.5×2.7+35×0.733.5×2.7-3.5×0.7(32+5.6)÷0.8 3.5÷0.6-0.5÷0.64.9÷1.47÷0.25÷47÷0.1257.35÷(7.35×0.25)7.35÷(7.35÷0.25)3.07-0.38-1.62 1.29+3.7+2.71+6.38-2.45-1.55 3.25+1.79-0.59+1.7523.4-0.8-13.4-7.2 0.32×4033.2+0.36+4.8+1.64 1.23+3.4-0.23+6.6 0.25×3612.7-(3.7+0.84)36.54-1.76-4.54 0.25×0.73×4 7.6×0.8+0.2×7.6 0.85×199 0.25×8.5×4 1.28×8.6+0.72×8.6 12.5×0.96×0.8 10.4-9.6×0.350.8×(4.3×1.25) 3.12+3.12×99 28.6×101-28.6 (4.23+6.17)×0.8 0.86×15.7-0.86×14.7 2.4×10214-7.32-2.68 2.64+8.67+7.36+11.33答案3.29+0.73+2.27 3.29-0.73-2.27 7.5+2.5-7.5+2.5=3.29+(0.73+2.27) =3.29-(0.73+2.27) =(7.5-7.5)+(2.5+2.5)=3.29+3 =3.29-3 =0+5=6.29 =0.29 =5(加法结合律)(减法的性质)(同级运算交换)7.325-3.29-3.325 7.325-(5.325+1.7)=7.325-3.325-3.29 =7.325-5.325-1.7=4-3.29 =2-1.7=0.71 =0.3(减法交换)(减法的性质)3.29+0.73-2.29+2.27 3.29×0.25×4 0.125×8.8=(3.29-2.29)+(0.73+2.27)=3.29×(0.25×4)=0.125×8×1.1=1+3 =3.29×1 =1×1.1=4 =3.29 =1.1(同级运算交换)(乘法结合律)(先拆数,乘法结合律)0.25×0.28 0.125×3.2×2.5 35×10.2=0.25×4×0.07 =(0.125×8)×(0.4×2.5)=35×(10+0.2)=1×0.07 =1×1 =35×10+35×0.2=0.07 =1 =350+7(先拆数,乘法结合律)(拆数,乘法结合律) =357(拆数,乘法分配律)0.25×4÷0.25×4=(0.25÷0.25)×(4×4)=1×16=16(同级运算交换)3.5×101-3.5 3.5×9.9+3.5×0.1 ★ 3.5×2.7+35×0.73=3.5×(101-1)=3.5×(9.9+0.1)=3.5×2.7+3.5×7.3=3.5×100 =3.5×10 =3.5×(2.7+7.3)=350 =35 =3.5×10(乘法分配律)(乘法分配律) =35(先利用积不变的规律转化,然后再用乘法分配律)3.5×2.7-3.5×0.7 ★ (32+5.6)÷0.8 ★ 3.5÷0.6-0.5÷0.6=3.5×(2.7-0.7)=32÷0.8+5.6÷0.8 =(3.5-0.5)÷0.6=3.5×2 =40+7 =3÷0.6=7 =47 =5(乘法分配律)(后 2 题类似分配律,但只适用于(a+b)÷c和(a-b)÷c,而a÷(b+c)和a÷(b-c)不能用。
五年级上册数学简便计算30道题及答案
五年级上册数学简便计算30道题及答案1、24.6-3.98+5.4-6.02解析:此题利用加法交换结合律,凑整再计算。
步骤如下:24.6-3.98+5.4-6.02=(24.6+5.4)-(3.98+6.02)=30-10=202、27×17/26解析:此题先用加法分配律,把27转换成(26+1),再利用乘法结合律,使得运算简便。
27×17/26=(26+1)×17/26=26×17/26+1×17/26=17+17/26=17又17/263、528-99解析:利用凑整法和减法结合律计算,先利用凑整法把99变换为(100-1),再运用a-b-c=a-(b+c)来简便计算,步骤如下:528-99=528-(100-1)=528-100+1=428+1=4294、1.2×2.5+0.8×2.5解析:运用提取公因数的方法,公式:ac+ab=a(b+c),提取公因数2.5,1.2和0.8相加正好凑整数,使得运算简便。
1.2×2.5+0.8×2.5=(1.2+0.8)×2.5=2×2.5=55、2.96×40解析:此题先利用乘法分配律,把2.96×40转换成29.6x4,再利用乘法结合律来简便计算。
2.96×40=29.6x4=(30-0.4)x4=30×4+0.4×4=120-1.6=118.46、0.36 x 1.5 - 0.45解析:此题运用乘法分配律,把0.45转换成1.5 x 0.3 ,即可提取公因数1.5,再根据乘法结合律进行简便计算。
0.36 x 1.5 - 0.45= 0.36 x 1.5 - 1.5 x 0.3= 1.5 × (0.36 - 0.3)= 1.5 × 0.06= 0.097、46×44/45解析:此题先利用加法分配律把46转换成(45+1),再利用乘法结合律:(a×b)×c=a×(b×c)使得运算简便。
五年级上册数学简便计算练习题及答案
五年级上册数学简便计算练习题及答案请用简便方法计算下列各题0.25×0.20.125×3.2×2.535×40.20.25×4÷0.25×4.5×9.93.5×99+3.53.5×101-3.53.53.5×2.7-3.5×0.74.9÷3.57.35÷.353.29+0.73+2.273.29-0.73-2.2.5+2.5-7.5+2.57.325-3.29-3.32.325-7.325-×9.9+3.5×0.1.5÷0..5÷0.25÷÷7.325-×2.7+35×0.7÷0.6-0.5÷0.÷0.12÷83.29+0.73-2.29+2.23.29×0.25×0.125×8.863.4÷2.5÷0..9÷1.4.9÷÷0.70.35×1.25×2×0.828.6×101-28.614-7.32-2.62.64×0.47.6×0.8+0.2×7.60.25×362.5×2.432.4×0.9+0.1×32.40.86×15.7-0.86×14.7+8.67+7.36+11.39.16×1.5-0.5×9.163.60.85×19 ×3.2×2.552.7÷4515÷0.252.4×102.31×1.2×0.5-3.6×0.0.25×8.5×4×40.20.125小学数学五年级上册简便计算归类练习一、当一个计算题只有同一级运算又没有括号时,我们可以“带符号搬家”.12.06+5.07+2.90.34+9.76-10.3425×7×434÷4÷1. 1.25÷25×0.102×7.3÷5.1二A、当一个计算题只有加减运算又没有括号时,我们可以在加号后面直接添括号,括到括号里的运算原来是加还是加,是减还是减.但是在减号后面添括号时,括到括号里的运算,原来是加,现在就要变为减;原来是减,现在就要变为加.a+b+c=a+ ,a+b-c=a +,a-b+c=a –,a-b-c= a-33-15.7-4.41.06-19.72-20.28.29+0.73-2.29+2.277.325-.29-0.73-2.27.325-.325-B、当一运算,原来是乘还是乘,是除还是除.但是在除号后面添括号时,括到括号里的运算,原来是乘,现在就要变为除;原来是除,现在就要变为乘.a×b×c=a×, a×b÷c=a×, a÷b÷c=a÷ ,a÷b×c=a÷,700÷14÷ 18.6÷2.5÷0.1.96÷0.5÷1.06×2.5×47÷0.25÷÷0.12÷.9÷三A、当一个计算题只有加减运算又有括号时,我们可以将加号后面的括号直接去掉,原来是加现在还是加,是减还是减.但是将减号后面的括号去掉时,原来括号里的加,现在要变为减;原来是减,现在就要变为加.5.68+19.68-B、当一个计算题只有乘除运算又有括号时,我们可以将乘号后面的括号直接去掉,原来是乘还是乘,是除还是除.但是将除号后面的括号去掉时,原来括号里的乘,现在就要变为除;原来是除,现在就要变为乘.0.25×1.25× .35÷四、乘法分配律的两种典型类型A,、括号里是加或减运算,与另一个数相乘,注意分配÷0. ×0.4÷0.7B、注意相同因数的提取.0.92×1.41+0.92×8.590.86×15.7-0.86×14.73.5÷0.6-0.5÷0.61.3×11.6-1.6×1..5×9.9+3.5×0.1.5×2.7+35×0.733.5×2.7-3.5×0.732.4×0.9+0.1×32..6×0.8+0.2×7.69.16×1.5-0.5×9.16五、一些简算小技巧A、巧借,可要注意还哦 ,有借有还,再借不难.9999+999+99+94821-998B、分拆,可不要改变数的大小哦3.2×12.5×251.25×88.6×0.25C/注意构造,让我们的算式满足乘法分配律的条件1.8×99+ 1.83.8×9.9+0.3.6×9.913.5×27+13.5×72+13.51.01×9. 102×0.83.5×101-3.5.5×9.9.5×99+3.50.67×10.1-6.3.6-3.6×0.50.85×1990.25×8.5×428.6×101-28.62.4×1020.25×3 0.125×3.2×2.55×40.22.31×1.2×0. 15÷0.2.5×2.4×40.20.125×8.80.25×0.280.125×3.2×2.528×21.6-2.8×16.6×1.7+0.56×83请用简便方法计算下列各题0.25×4÷0.25×4.9÷3.53.29+0.73+2.22.7÷457.325-3.29-3.3250.35×1.25×2×0.83.29×0.25×3.4÷2.5÷0..9÷1.414-7.32-2.62.64+8.67+7.36+11.33 五年级上册简便算法题10÷3.14-6.86÷3.1437.68÷0.25÷43.75-37.56-0.77÷144.5×9.80.7÷0.1250.7÷0.252.5×3.2×12.512.5×9.6×0.253.75-37.65÷0.4÷0.253.125÷8÷0.12537.65-4.75-3.2525×6.4×12.53.6×0.25答案10÷3.14-6.86÷3.1=÷3.1=3.14÷3.1=137.68÷0.25÷=37.68÷ =37.68÷1 =37.68 3.75- =3.75-2.75+1.=1+1.=2.337.56-=37.56-7.56-1=30-1=10.77÷1=0.77÷7÷=0.11÷=0.054.5×9.8=4.5× =4.5×10- 4.5×0.=45-0.=44.1 0.7÷0.125=÷ =0.56÷1 =0.50.7÷0.25=÷ =2.8÷1 =2.82.5×3.2×12.=× =1×100 =10012.5×9.6×0.25=×3× =10×3×1 =303.75- =3.75+1.25-2.8=5-2.=2.237.65÷0.4÷0.25.125÷8÷0.1257.65- 4.75-3.225×6.4×12.=25×4×0.2×8×12.5.6×0.2=×0.25.4÷9+5.6÷=。
小学数学五年级上册简便计算68道题(含详细答案)
小学数学五年级上册简便计算68道题(含详细答案)3.29+0.73+2.273.29-0.73-2.277.5+2.5-7.5+2.57.325-3.29-3.3257.325-(5.325+1.7)7.325-(5.325-1.7)3.29+0.73-2.29+2.273.29×0.25×40.125×8.8零点二五×0.280.125×三点二二×二点五三五×10.20.25×4÷0.25×四3.5×9.93.5×99+3.5三点五×101-3.53.5×9.9+3.5×0.13.5×2.7+35×零点七三1三点五×2.7-3.5×0.7(32+5.6)÷0.83.5÷0.6-0.5÷0.64.9÷1.47÷0.25÷47÷0.1257.35÷(7.35 × 0.25)3.07-0.38-1.628-2.45-1.5523.4-0.8-13.4-7.27.35÷(7.35÷0.25)1.29+3.7+2.71+6.33.25+1.79-0.59+1.750.32×肆佰叁拾二元3.2+0.36+4.8+1.641.23+3.4-0.23+6.60.25×3612.7-(3.7+0.84)36.54-1.76-4.540.25×零点七三×四7.6×0.8+0.2×7.61.28×8.6+0.72×8.60.8×(4.3×1.25)3.12(4.23+6.17)×零点八14-7.32-2.68零点八五×一千九百九十九点二五×八点五×四百一十二点五×零点九六×0.810.4-9.6×0.35+3.12×九千九百二十八点六×101-28.60.86×15.7-0.86×14.72×一百零二2.64+8.67+7.36+11.332.31×1.2×0.5三(2.5-0.25)×0.49.16×1.5-0.5×9.163.6-3.6 × 0.54.5÷1.8930÷0.6÷563.4÷2.5÷0.44.25÷2.5×9.9+0.173.9÷(1.3 × 5)(7.7+1.54)÷0.72.5×2.42.7÷45零点三五×一点二五×二×0.832.4×0.9+0.1×三十二点四15÷0.2515÷(0.15×0.4)四小学数学五年级上册简便计算练习(答案卷)一、分类工作:3.29+0.73+2.273.29-0.73-2.277.5+2.5-7.5+2.5=3.29+(0.73+2.27)=3.29-(0.73+2.27)=(7.5-7.5)+(2.5+2.5)=3.29+3=3.29-3=0+5=6.29=0.29=5(加法组合定律)(减法性质)(同级运算交换)7.325-3.29-3.3257.325-(5.325+1.7)7.325-(5.325-1.7)=7.325-3.325-3.29=7.325-5.325-1.7=7.325-5.325+1.7=4-3.29=2-1.7=2+1.7=0.71=0.3=3.7(减法交换)(减法的本质)(前面有减号,从括号中变成一个符号)3.29+0.73-2.29+2.273.29×0.25×40.125×8.8=(3.29-2.29)+(0.73+2.27)=3.29×(0.25×4)=0.125×8×1.1=1+3=3.29×1=1×1.1=4=3.29=1.1(同级运算交换)(乘法组合法则)(第一次分割数,乘法组合法则)0.25×0.280.125×3.2×2.535×10.2=0.25×4×0.07=(0.125×8)×(0.4×2.5)=35×(10+0.2)=1×0.07=1×1=35×10+35×0.2=0.07=1=350+7(先拆数,乘法结合律)(拆数,乘法结合律)=357(拆数,乘法分配律)零点二五×4÷0.25×四十三点五×9.93.5×99+3.5=(0.25÷0.25)×(4×4)=3.5×(10-0.1)=3.5×(99+1)=1×16=3.5×10-3.5×0.1=3.5×100=16=35-0.35=350(同级运算交换)=34.65(乘法分配律)(分裂数,乘法分布定律)3.5×101-3.53.5×9.9+3.5×0.1★3.5×2.7+35×0.73=3.5×(101-1)=3.5×(9.9+0.1)=3.5×2.7+3.5×7.3=3.5×100=3.5×10=3.5×(2.7+7.3)=350=35=3.5×10(乘法分配律)(乘法分配律)=35(首先使用乘积不变性定律进行变换,然后再用乘法分配律)五。
小学数学五年级上册简便计算68道题(含详细规范标准答案)
小学数学五年级上册简便计算68道题(含详细规范标准答案)一、加减法简便计算1. 123 + 456 = 5792. 789 321 = 4683. 678 + 123 456 = 3454. 456 + 789 123 = 11225. 987 + 654 321 = 13206. 789 + 456 123 = 11227. 654 + 321 987 = 3128. 321 + 987 654 = 6549. 123 + 456 + 789 = 136810. 456 + 789 + 123 = 1368二、乘除法简便计算11. 7 × 8 = 5612. 9 ÷ 3 = 313. 12 × 13 = 15614. 15 ÷ 5 = 315. 18 × 19 = 34216. 21 ÷ 7 = 317. 24 × 25 = 60018. 27 ÷ 9 = 319. 30 × 31 = 93020. 33 ÷ 11 = 3三、混合运算简便计算21. 12 + 7 × 8 = 6822. 9 ÷ 3 + 6 = 723. 12 × 13 45 = 14124. 15 ÷ 5 + 8 = 725. 18 × 19 + 21 = 35726. 21 ÷ 7 4 = 127. 24 × 25 12 = 58828. 27 ÷ 9 + 3 = 629. 30 × 31 15 = 91530. 33 ÷ 11 2 = 1四、分数简便计算31. 1/2 + 1/3 = 5/632. 2/3 ÷ 1/4 = 8/333. 3/4 + 1/2 = 5/434. 4/5 ÷ 1/2 = 8/535. 5/6 + 1/3 = 7/636. 6/7 ÷ 1/4 = 24/737. 7/8 + 1/2 = 11/838. 8/9 ÷ 1/3 = 839. 9/10 + 1/5 = 13/1040. 10/11 ÷ 1/2 = 20/11五、小数简便计算41. 0.5 + 0.3 = 0.842. 0.6 ÷ 0.2 = 343. 0.7 × 0.8 = 0.5644. 0.4 ÷ 0.4 = 145. 0.9 + 0.1 = 146. 0.8 ÷ 0.2 = 447. 0.7 × 0.9 = 0.6348. 0.6 ÷ 0.3 = 249. 0.5 + 0.2 = 0.750. 0.4 ÷ 0.2 = 2六、百分数简便计算51. 20% + 30% = 50%52. 40% ÷ 20% = 253. 50% × 80% = 40%54. 25% + 75% = 100%55. 60% ÷ 30% = 256. 70% × 50% = 35%57. 80% + 20% = 100%58. 90% ÷ 10% = 959. 55% × 45% = 24.75%60. 65% + 35% = 100%七、方程简便计算61. 2x + 3 = 7,解得 x = 262. 3x 4 = 5,解得 x = 363. 4x + 5 = 9,解得 x = 164. 5x 6 = 4,解得 x = 265. 6x + 7 = 13,解得 x = 166. 7x 8 = 9,解得 x = 367. 8x + 9 = 17,解得 x = 168. 9x 10 = 11,解得 x = 3八、应用题简便计算69. 小华有10个苹果,小明有15个苹果,他们一共有多少个苹果?解:10 + 15 = 25个苹果。