Question

口算 3.2×0.2	1.4×0.4	3.3÷3	1.2÷0.3
2.5×0.4	1.5×2	0.7×7	7.3+0.3
0.53-0.3	1.8×0.5	0.9×0.01	0.23×3
（5）2-1.2	7.8÷6	8.4÷0.21	8.4÷0.7
5.6+3.6	9-2.35	0.56÷8	1.23×3
5.6÷0.4	4.5÷0.9	8.1×2	90÷3
1.23+3	5.6+1.23	4.5×2	5.6÷1.4
4.8÷1.2	7.2÷0.9	6.6÷1.1	7.2÷6
2.1÷3	0.6×0.5	3.23×2	1.8÷3
12.5÷0.1	0.32÷0.8	1.6+3.7	0.45×0.2
0.36÷1.8	0.4×0.5	8.4+5.6	8.4÷2.1
4.8÷0.08	4.8÷0.8	3+2.3	9.3÷3
0.01×8	7.31×100	0.09×6	0.8×0.6
1.25×8	3÷5	2.3+2.3	6.23+3.6

Answer 1

分析：直接根據小數四則運算的法則進行計算．

解答：解：口算
（1）3.2×0.2=0.64             1.4×0.4=0.56         3.3÷3=1.1         1.2÷0.3=4
（2）2.5×0.4=1                1.5×2=3             0.7×7=4.9           7.3+0.3=7.6
（3）0.53-0.3=0.23            1.8×0.5=0.9          0.9×0.01=0.009       0.23×3=0.69
（4）0.56÷8=0.07             1.23×3=3.69           1.6÷0.04=40        7.3+2.7=10
（5）2-1.2=0.8                7.8÷6=1.3            8.4÷0.21=40         8.4÷0.7=12
（6）5.6+3.6=9.2              9-2.35=6.65           0.56÷8=0.07        1.23×3=3.69
（7）5.6÷0.4=14              4.5÷0.9=5            8.1×2=16.2         90÷3=30
（8）1.23+3=4.23              5.6+1.23=6.83          4.5×2=9           5.6÷1.4=4
（9）4.8÷1.2=4               7.2÷0.9=8           6.6÷1.1=6           7.2÷6=1.2
（10）2.1÷3=0.7             0.6×0.5=0.3          3.23×2=6.46         1.8÷3=0.6
（11）12.5÷0.1=125          0.32÷0.8=0.4         1.6+3.7=5.3          0.45×0.2=0.09
（12）0.36÷1.8=0.2          0.4×0.5=0.2           8.4+5.6=14          8.4÷2.1=4
（13）4.8÷0.08=60            4.8÷0.8=6           3+2.3=5.3            9.3÷3=3.1
（14）0.01×8=0.08           7.31×100=731         0.09×6=0.54        0.8×0.6=0.48
（15）1.25×8=10             3÷5=0.6              2.3+2.3=4.6          6.23+3.6=9.83．

點評：此題主要考查小數四則運算的口算能力．