84*0.25+2.5*16 简便计算
问题描述：
84*0.25+2.5*16 简便计算
答
84×0.25+2.5×16
=（21×4）×0.25+（4×4）×2.5
=21×（4×0.25）+4×（4×2.5）
=21×1+4×10
=21+40
=61