Question

7．口算我能行

2.5×0.4=	2.3×0.2=	2.1÷0.3=	7.1×0.4=
4.5÷0.15=	1-0.07=	0.42÷0.7=	12.4÷4=
2.5+1.5=	5.9×0.2=	0.48÷0.8=	0.25×1.3×4=
20÷0.01=	9÷0.01=	5.5÷1.1=	4.79+15.21=
0.3÷0.03=	0.2×0.1=	3.6+6.4=	0.56÷0.28=
1.2×0.3=

Answer 1

分析 根据小数加减乘除法的计算方法进行解答即可．注意0.25×1.3×4变形为0.25×4×1.3计算．

解答 解：

2.5×0.4=1	2.3×0.2=0.46	2.1÷0.3=7	7.1×0.4=2.84
4.5÷0.15=30	1-0.07=0.93	0.42÷0.7=0.6	12.4÷4=3.1
2.5+1.5=4	5.9×0.2=1.18	0.48÷0.8=0.6	0.25×1.3×4=1.3
20÷0.01=2000	9÷0.01=900	5.5÷1.1=5	4.79+15.21=20
0.3÷0.03=10	0.2×0.1=0.02	3.6+6.4=10	0.56÷0.28=2
1.2×0.3=0.36

点评 考查了小数加减乘除法运算，关键是熟练掌握计算方法进行解答即可．