Question

3.57+6.45.8-1.23简便运算？

Answer 1

计算如下：
3.57+6.45.8-1.23
=3.57+(6.45.8-1.23)
=3.57+5.22
=8.79

Answer 2

用凑整法可使运算简便一些。
3.57+6.4-5.8-1.23
=3+0.5+0.07+6+0.4-6+0.2-1-0.2-0.03
=(3+6-6-1)+(0.5+0.4+0.2-0.2)+(0.07-0.03)
=2+0.9+0.04
=2.94。