Question

54.9×0.38=用简便计算怎么算？

Answer 1

54.9*0.38=54.9*(0.4-0.02)=21.96-10.98=10.98

Answer 2

简便计算
54.9×0.38
=（55-0.1）×0.38
=55×0.38-0.1×0.38
=20.9-0.038
=20.862