下面各题怎样简便就怎样计算9.9×25 3.25×4.7-7.8 1.25×3

2024-12-03 22:39:55
推荐回答(1个)
回答1:

(1)9.9×25,
=(10-0.1)×25,
=250-2.5,
=247.5;

(2)3.25×4.7-7.8,
=15.275-7.8,
=7.475;

(3)1.25×32×0.25,
=1.25×8×4×0.25,
=(1.25×8)×(4×0.25),
=10×1,
=10;

(4)8.12×4+1.88×4,
=(8.12+1.88)×4,
=10×4,
=40.