54.9×0.38…………求简便运算!

分类: 作业答案 • 2021-11-13 00:43:09

问题描述：

54.9×0.38…………求简便运算!

答

54.9X0.38=(55-0.1)X(0.4-0.02)
=55X0.4-55X0.02-0.1X0.4+0.1X0.02
=22-1.1-0.04+0.002
=20.862蟹蟹no