Question

8．口算

1.5×7=	9.1÷70=	2.3×0.6=	8.4÷6=	6.21-3.2=
2.8×40=	3.2×0.25=	0.6×0.15=	3-1.36=	0.65÷5=
1.8-0.88=	1.9×5=	7.84+2.16=	0.17×10=	5.25+2.75=
4.58-1.64=	2.07+0.28=	0÷0.27=	0.68÷0.4=	3÷20=
1.05-0.37=	5.6÷100=	10.6+3.25=	2.48+3.66=	2.7×0.8=
6.9÷0.3=	7.5÷0.5=	1.25×8×10=	0.25×40÷0.5=	5.6×0.99+5.6×0.01=

Answer 1

分析 根据小数加减乘除法运算的计算法则计算即可求解．注意3.2×0.25变形为0.8×（4×0.25）计算，5.6×0.99+5.6×0.01根据乘法分配律计算．

解答 解：

1.5×7=10.5	9.1÷70=0.13	2.3×0.6=1.38	8.4÷6=1.4	6.21-3.2=3.01
2.8×40=112	3.2×0.25=0.8	0.6×0.15=0.09	3-1.36=1.64	0.65÷5=0.13
1.8-0.88=0.92	1.9×5=9.5	7.84+2.16=10	0.17×10=1.7	5.25+2.75=8
4.58-1.64=2.94	2.07+0.28=2.35	0÷0.27=0	0.68÷0.4=1.7	3÷20=0.15
1.05-0.37=0.68	5.6÷100=0.056	10.6+3.25=13.85	2.48+3.66=6.14	2.7×0.8=2.16
6.9÷0.3=23	7.5÷0.5=15	1.25×8×10=100	0.25×40÷0.5=20	5.6×0.99+5.6×0.01=5.6

点评 考查了小数加减乘除法运算，关键是熟练掌握计算法则正确进行计算．