5.25*8.2 5.25*0.8 0.25怎么用简便方法计算?
问题描述：
5.25*8.2 5.25*0.8 0.25怎么用简便方法计算?
答
5.25*8.2 +5.25*0.8+ 0.25
=(5+0.25)x8.2 +5.25x0.8+ 0.25
=5x8.2+0.25x8.2 +5.25x0.8+ 0.25
=41+0.25x(8.2+0.8+1)
=41+0.25x10
=41+2.5
=43.5