116问答网 > 下面各题，怎样简便就怎样算：①2.8×0.5+0.5×27.2 &nbs...

下面各题，怎样简便就怎样算：①2.8×0.5+0.5×27.2 &nbs...

2025-06-23 09:45:10

推荐回答（1个）

回答1：

①2.8×0.5+0.5×27.2
=（2.8+27.2）×0.5
=30×0.5
=15

②1.25×64×0.25
=1.25×8×4×2×0.25
=（1.25×8）×（4×0.25）×2
=10×1×2
=20

③7.67-2.57-2.43
=7.67-（2.57+2.43）
=7.67-5
=2.67

④6.1×0.98
=6.1×（1-0.02）
=6.1×1-6.1×0.02
=6.1-0.122
=5.978