7.9*2.5+2.2*2.5-0.25的简便算法
问题描述:
7.9*2.5+2.2*2.5-0.25的简便算法
答
7.9×2.5+2.2×2.5-0.25
=7.9×2.5+2.2×2.5-2.5×0.1
=(7.9+2.2-0.1)×2.5
=10×2.5
=25