Question

一道小学计算题(要有因为所以及步骤)

(1)0.649*(1/5 - 1/2)
老师出的,怎么做?

Answer 1

0.649*(1/5 - 1/2)
=0.649*(0.2-0.5)
=0.649*(-0.3)
=-0.1947

Answer 2

*是乘号吗?如果是,就是这样做:

0.649×(1/5—1/2)
≡0.649×(2/10-5/10)
≡0,649×7/10
≡47.94