999*7.78+333*6.66的简算方法!
问题描述:
999*7.78+333*6.66的简算方法!
答
999*7.78+333*6.66
=999*7.78+333*3*2.22
=999*7.78+999*2.22
=999*(7.78+2.22)
=999*10
=9990