几道数学简算题

问题描述:

几道数学简算题
5.3+2.55/1.7
(70+0.42)/7
4.2/28

5.3+2.55/1.7=5.3+1.5=6.8
(70+0.42)/7=70.42/7=10.06
4.2/28=0.15