9.9*7.8怎么简便计算
问题描述:
9.9*7.8怎么简便计算
答
10*7.8-0.1*7.8
答
9.9*7.8=(10-0.1)*7.8=10*7.8-0.1*7.8=77.22
答
9.9*7.8
=(10-0.1)*7.8
=78-0.78
=77.22
答
(10-0.1)*7.8=78-0.78=77.22