Question

3.69×0.8 6.31×0.8-3.8怎么用简便方法算

3.69×0.8 6.31×0.8-3.8怎么用简便方法算

Answer 1

3.69×0.8 +6.31×0.8-3.8
=0.8×（3.69+6.31）-3.8
=0.8×10-3.8
=8-3.8
=4.2