用简便方法计算0.21*6.4+0.42*1.8怎么算?
问题描述:
用简便方法计算0.21*6.4+0.42*1.8怎么算?
答
0.21*6.4+0.42*1.8
=0.21×6.4+0.21×3.6
=0.21×(6.4+3.6)
=0.21×10
=2.1