6.4×0.125×12.5的简便计算

问题描述:

6.4×0.125×12.5的简便计算

6.4=8*8*1/10
0.125=1/8
12.5=100*0.125=100*1/8
6.4×0.125×12.5=8*8*1/10×1/8×100*1/8=1/10*100=10

把6.4 写成0.8*8
0.8*8*0.125*12.5
= 0.8*(8*0.125)*12.5
= 0.8*1*12.5
= 0.8*12.5
= 10

记住一个公式 8*125 = 1000
类似还有 4*25 = 100等等

6.4×0.125×12.5
=(8×0.125)×(0.8×12.5)
=1×10
=10