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
