计算下面各题。你认为怎样简便就怎样算。 54.9*0.38，4.05+37.85,1.25*0.7

Question

计算下面各题。你认为怎样简便就怎样算。
54.9*0.38，4.05+37.85,1.25*0.7*0.8,
9.8*25,6.1*3.6+3.6*3.9,2.96*40

Answer 1

54.9×0.38=20.862

4.05+37.85=41.9
1.25×0.8×0.7
=1×0.7
=0.7

9.8×25=245
6.1×3.6+3.6×3.9
=（6.1+3.9）×3.6
=10×3.6
=36

2.96×40=118.4

Answer 2

一、=（55-0.1）*0.38=55*0.38-0.1*0.38=20.9-0.038=20.52
二、=4+0.05+38-0.15=42-0.1=41.9
三、=（1.25*0.8）*0.7=1*0.7=0.7
四、=（10-0.2）*25=10*25-0.2*25=250-5=245
五、=3.6*（6.1+3.9）=3.6*10=36
六、=（3-0.04）*40=3*40-0.04*40=120-1.6=118.4

Answer 3

Answer 4

20.862,41.9,（1.25*0.8）*0.7=10*0.7=7,245,36,118.4