Question

5.2×2-0.5×0.8的简便算法

Answer 1

2.5*0.8-0.5*1.8
=2.5×0.8-0.5×（1+0.8）
=2.5×0.8-0.5×1-0.5×0.8
=（2.5×0.8-0.5×0.8）-0.5×1
=（2.5-0.5）×0.8-0.5
=2×0.8-0.5
=1.6-0.5
=1.1