Question

用简便方法计算∶333x66.6十778X99.9

Answer 1

原式=（333x3）x（66.6÷3）+778×99.9
=999x22.2+778x99.9
=999x22.2+77.8x999
=999x（22.2+77.8）
=999x100
=99900

Answer 2

333×66.6＋778×99.9
=333×66.6＋778×333×0.3
=333×(66.6＋778×0.3)
=333×(66.6＋233.4)
=333×300
=999000

Answer 3

333×66.6+778×99.9
=（333×3/10）×（66.6/3*10）+778×99.9
= 99.9×222+778×99.9
=（222+778）×99.9
= 1000×99.9
= 99900

追问

怎么想到这样做！