Question

计算下面各题，能简算的用简便方法算．（1）0.8×3.9×1.25 &n...

计算下面各题，能简算的用简便方法算．（1）0.8×3.9×1.25 （2）3.6×10.1（3）4.8×1.25 （4）4.87×2.34+48.7×0.266．

Answer 1

（1）0.8×3.9×1.25
=0.8×1.25×3.9
=1×3.9
=3.9；

（2）3.6×10.1
=3.6×（10+0.1）
=3.6×10+3.6×0.1
=36+0.36
=36.36；

（3）4.8×1.25
=6×0.8×1.25
=6×（0.8×1.25）
=6×1
=6；

（4）4.87×2.34+48.7×0.266
=4.87×2.34+4.87×2.66
=4.87×（2.34+2.66）
=4.87×5
=24.35．