999*7.78+333*6.66=?(要简算)

问题描述:

999*7.78+333*6.66=?(要简算)

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