四年级小数简便运算及答案ppt课件

=9.47
6.3+15.4+0.09+3.7+14.6 56.8+22.8 34.65－0.99－0.97
=(6.3+3.7)+(14.6+15.4)+0.09 =40+0.09
=56.8+23－0.2 =79.8－0.2
=34.65－1－1+(0.01+ =32.65+0.04
=40.09
=79.6
=37.32
30.16－23.28+15.28 0.25×4.78×4
=30. 16－(23.28－15.28) =0.25×4×4.78
=30.16－8
=1×4.78
=22.16
来自百度文库
=4.78
.
0.98×2.5 = (1－0.02) ×2.5
=1×2.5－0.02×2.5
=2.5－0.05
=2.45
3
3.65－1.28－0.37－1.77
=3.65－(1.28+0.37) －1.77 =3.65－1.65 －1.77 =0.23
19.826－1.173－5.248－3.405
=19.826－(1.173+5.248+3.405 ) =19.826－9.826 =10
130.8－35.9+5.9
=130. 8－(35.9－5.9) =130.8－30 =100.8
=3.8
36×2.54+1.8×49.2 =1.8×20×2.54+1.8×49.2 =1.8×(20×2.54)+1.8×49.2 =1.8×(50.8+49.2) =1.8×100
91÷0.125 =(91×8)÷(0.125×8） =728÷1 =728
2.38×4.1+5.8×2.38+0.238
=2.38×4.1+5.8×2.38+2.38×0.1
=2.38 ×(4.1+5.8+0.1）
=2.38×10
=23.8
.
28.7×1.6÷28.7 = 28.7÷28.7×1.6 =1×1.6 =1.6
0.25×7×3.6
1.25×13×1.6
10.2×0.41
=0.25×7×(4×0.9） =0.25×4×7×0.9 =1×7×0.9
===111..022×551××318××30×.1(238××00..22）===14(0.1×10+0+0.0.4.0128+2）0×.20×.401.41
=6.3
=26
=4.182
4.52×0.45+5.48×0.45 =(4.52+5.48）×0.45 =10×0.45
=4.5
42×3.9 = 42×(4－0.1） =42×4－42×0.1 =168－4.2
=163.8
1.4×99+1.4 =1.4×(99+1） =1.4×100 =140
2.5×12.5×32
一、用简便方法计算下面各题：
48.7+5.6+11.3 43.21+98.76+56.79+1.24
5.48+3.99
=48.7+11.3+5.6 =(43.21+56.79)+(98.76+1.24)=5.48+(4－0.01)
=60+5.6
=100+100
=5.48+4－0.01
=65.6
=200
42×67+4.2×330
=2.5×12.5×(8×4） =42×67+42×33
=(2.5×4)×(12.5×8) =42×(67+33）
=10×100
=42×100
=1000
=4200 .
8.37×16÷8 =8.37×(16÷8） =8.37×2 =16.74
4
28.7÷0.35
310÷2.5÷4
=32.69
34.5－2.98 =34.5－3+0.02 =31.5+0.02 =31.52
45.7－10.4 =45.7－10－0.4 =35.7－0.4
=35.3
57.3－27.8
=57.3－28+0.2 =29.3+0.2 =29.5
.
1
67.68－7.3－2.7
=67.68－(7.3+2.7) =67.68－10 =57.68
23.97+0.9+6.8 23.9+6.78－3.9
=23.97+1+ 7－0.3 =23.9－3.9+6.78
=31.97－0.3
=20+6.78
=31.67
=26.78 .
31.61－21.27－1.61 =31.61－1.61 －21.27 =30－21.27
=8.73
2
27.64－(5.79+1.64) =27.64－1.64 －5.79 =26－5.79
6
7.6×18+2.3×2.4
1.62÷8÷(3.62－2.37) =1.62÷8÷1.25
=1.62÷(8×1.25）
=1.62÷10
=0.162
0.38×7.6+0.38÷2.5+0.38×2 =0.38×7.6+0.38×0.4+0.38×2 =0.38×(7.6+0.4+2) =0.38×10
=28.7÷(0.7×0.5）=310÷(2.5×4）
=28.7÷0.7÷0.5 =310÷10
=41÷0.5
=31
=82
560÷(140÷8)
=560÷140×8 =4×8 =32
5.6×7÷4 =5.6÷4×7 =1.4×7 =9.8
11.2÷ 9.6×2.4 =11.2÷(9.6÷2.4） =11.2÷4 =2.8
5
11÷0.25－10÷0.25 =(11 －10)÷0.25 =1÷0.25 =4
(80+5.6)÷8 =80÷8+5.6÷8 =10+0.7 =10.7
7.8×(1.001÷0.26)×0.26 =7.8×1.001×(0.26÷0.26) =7.8×1.001
=7.8078
3.5+17.8×99+14.3 =(3.5+14.3)+17.8×99 =17.8×(1+99） =17.8×100
=1780
100×9.5×0.98+9.5×2
=100×0.98×9.5+9.5×2 =9.5×(98+2） =9.5×100 =950
28×11.11+99.99×8 =28×11.11+11.11×9×8
=28×11.11+11.11×(9×8)
=11.11×(28+72）
=11.11×100
. =1111
=20.21
23.12－(10.12－3.67) =23.12－10.12+3.67 =13+3.67 =16.67
20.65－(17.1－1.35)
=20.65+1.35－17.1 =22－17.1 =4.9
32.75+(15.25－10.68) =32.75+15.25－10.68 =48－10.68