66.6乘33.3怎么巧算
问题描述：
66.6乘33.3怎么巧算
答
原式=666×333/100
=222×3×333/100
=222×999/100
=2.22×（1000-1）
=2220-2.22
=2217+3-2.22
=2217+0.78
=2217.78