3.47乘6.9+6.53乘3.1+3.06乘1.9=

问题描述:

3.47乘6.9+6.53乘3.1+3.06乘1.9=
用简便方法

拆开计算
3.47×3.1+3.47×2×1.9+6.53×3.1+3.06×1.9
再合并
(3.47+6.53)×3.1+(3.47×2+3.06)×1.9
=10×3.1+10×1.9=31+19=50