0.8×0.25×0.4×12.5的简便方法

1、第一步，观察表达式0.8×0.25×0.4×12.5，知道8x125=1000，4x25= 100

0.8x0.25x0.4x12.5

= 0.8x12.5x0.4x0.25

2、第二步，进行转换12.5缩小10倍，0.4扩大10倍

0.8x0.25x0.4x12.5

= 0.8x12.5x0.4x0.25

= 0.8x1.25x4x0.25

3、第三步，由8x125=1000，0.8x1.25=1

0.8x0.25x0.4x12.5

= 0.8x12.5x0.4x0.25

= 0.8x1.25x4x0.25

= 1x4x0.25

4、第四步，4乘以25得100，缩小100倍

0.8×0.25×0.4×12.5

= 0.8x12.5x0.4x0.25

= 0.8x1.25x4x0.25

= 1 x 4 x 0.25

= 1 x 1

5、第五步，1乘以任何数，等于任何数

0.8×0.25×0.4×12.5

= 0.8x12.5x0.4x0.25

= 0.8x1.25x4x0.25

= 1 x 4 x 0.25

= 1 x 1

= 1

6、总结：

A x B x C x D

= A x C x B x D

= E x F

= G