Question

99.99乘77.78+33.33乘66.66用简便计算怎么算

急啊

Answer 1

33.33乘三分之二，66.66除以三分之二，就得到这样的式子：
99.99×77.78+22.22×99.99
=99.99×（77.78+22.22）
=99.99×100
=9999

Answer 2

99.99×77.78+33.33×66.66
=99.99×77.78+99.99×22.22
=99.99×（77.78+22.22）
=99.99×100
=9999

Answer 3

上式=99.99×（77.78+22.22）=99.99×100=9999