Question

4.6X1.25ⅹ7简便方法？

Answer 1

4.6X1.25ⅹ7
=(4+0.6)x1.25x7
=(4x1.25+0.6x1.25)x7
=(5+0.75)x7
=5x7+0.75x7
=35+5.25
=40.25
运用了乘法分配律，做起来比较简便。

Answer 2

4.6*1.25*7=4.6*0.5*5*5*7=
(5-0.4)*0.5*5*5*7=2.3*5*5*7=
11.5*5*7=57.5*7=287.5

Answer 3

1.25需要8这个朋友数凑整
4.6可以勉强拆分为8x0.575
所以原式=8x1.25x0.575x7
=10x0.575x7
=10x4.025
=40.25
这样就不用做拖式计算做多位数乘法，得以简便计算

如何？

Answer 4

把4.6改为4+0.6
(4+0.6)x1.25x7
=(4x1.25+0.6x1.25)x7
=(5+0.75)x7
=35+5.25
=40.25

Answer 5

4.6×1.25×7
=1.25x（4.6×7）
=1.25x32.2
=（1.25x8）x4.025
=10x4.025
=40.25
运用乘法结合律。