人教版五年级数学题p9.3.用简便方法计算。怎么做？

答案:6 悬赏:60 手机版

解决时间 2021-01-13 21:46

提问者网友：浮克旳回音
2021-01-13 14:59

最佳答案

五星知识达人网友：污到你湿
2021-01-13 16:17

9.3×(1.25×24)=9.3×(1.25×8×3)=9.3×30=279

2.5×(40+0.4)=2.5×40+2.5×0.4=101（04按0.4算）
或2.5×(40+04)=2.5×40+2.5×4=110（04按4算）

1.3×2.5+2.7×2.5 =2.5（1.3+2.7）=10
3.6×0.25=0.9×4×0.25=4×0.25×0.9=0.9

全部回答

1楼网友：过活
2021-01-13 18:55

第一题就错了，兄弟怎么给分呢？

2楼网友：爱难随人意
2021-01-13 18:08

1 9.3*1.25*24
=9.3*1.25*3*8
=(9.3*3)*(1.25*8)
=27.9*10
=279
2 2.5*(40+4)
=2.5*40+2.5*4
=100+10
=110
3 1.3*2.5+2.7*2.5
=(1.3+2.7)*2.5
=4*2.5
=10
4 3.6*0.25
=4*0.9*0.25
=(4*0.25)*0.9
=1*0.9
=0.9

3楼网友：渡鹤影
2021-01-13 17:18

9.3*1.25*24
=9.3*1.25*3*8
=(9.3*3)*(1.25*8)
=27.9*10
=279
2 2.5*(40+4)
=2.5*40+2.5*4
=100+10
=110
3 1.3*2.5+2.7*2.5
=(1.3+2.7)*2.5
=4*2.5
=10
4 3.6*0.25
=4*0.9*0.25
=(4*0.25)*0.9
=1*0.9
=0.9

4楼网友：人间朝暮
2021-01-13 17:05

1
9.3×(1.25×24)=9.3×(1.25×8×4)=9.3×40=372
2
2.5x40+2.5x4=100+10=110
3
(1.3+2.7)x2.5=4x2.5=10
4
4x0.9x0.25=0.9x1=0.9
给点分吧朋友= =

5楼网友：深街酒徒
2021-01-13 16:45

(1) 9.3×1.25×24
=9.3×(1.25×24)(乘法结合律）
=9.3×(1.25×8×3)
=9.3×(10×3)
=9.3×30
=279
(2) 2.5×(40+04)
=2.5×40+2.5×0.4 (乘法分配律）
=100+1
=101
（3）1.3×2.5+2.7×2.5
=2.5×（1.3+2.7）(乘法分配律）
=2.5×4
=10
（4）3.6×0.25
=0.9×4×0.25
=0.9×（4×0.25）)(乘法结合律）
=0.9

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