0.55*9.9简便计算

问题描述:

0.55*9.9简便计算

55/100 = 0.55
99/10 = 9.9
100*10 = 1000(记好这数)
55*99 = 55*100-55
55*100 = 5500
5500-55 = 5445
5445/1000 = 5.445
不知道你看懂了没

0.55乘(10-0.1)=5.5-0.055=5.445

0.55乘以(10-0.1)
=0.55*10-0.55*0.1
=5.5-0.051
5.445