80.5*2.8+143.5怎么简便计算

分类: 作业答案 • 2021-12-29 10:40:14

问题描述：

答

80.5*2.8+143.5
=80.5*(3-0.2)+143.5
=80.5*3-80.5*0.2+143.5
=241.5-16.1+143.5
=(241.5+143.5)-16.1
=385-16.1
=368.9