题目内容
2．| 30×0.5= | 0.78×0.2= | 340-127= |
| 10÷0.05= | 3.92+3.79= | 629-138= |
| 29.2-6.5= | 2.8-1.91= | 3.4×2= |
| 3.9×20= | 3.2+0.27= | 0.5×0.28= |
| 3.6÷0.02= | 24×9= | 2.5+5.6= |
| 0.8×0.9= | 1.5×8= | 2.8÷0.4= |
| 3.9-2.18= | 0.35×7= | 5.1÷1.7= |
| 720÷20= | 1.5×5= | 3.2÷4= |
| 2.6×4= | 8-0.125= | 72.6÷6= |
| 0.38+4.92= | 3.4×5= | 70.7÷7= |
| 3.8÷0.2= | 1.23+3.46= | 23.5-（3.5+6）= |
| 3.6×0.2= | 2.5×8= | 2.6×3÷2.6×3= |
| 3.18+0.43= | 1.2×25= | 25×2.4= |
| 4×0.25= | 6.5-0.8= | 33.9-2.5-7.5= |
| 1.4×0.7= | 5-2.1= | 7.25×4= |
| 3.18+2.78= | 3.75÷0.5= | 6.8÷0.25= |
| 6.24-0.38= | 3.14+5.7= | 170-25= |
| 3.4×0.7= | 3.28-1.8= | 162÷10= |
| 0.78-0.39= | 3.6×5= | 12.7-5+7.3= |
| 0.125×80= | 16.8÷21= | 1.9×40= |
分析 根据整数、小数加减乘除法的计算方法进行解答即可，23.5-（3.5+6）、33.9-2.5-7.5运用减法的性质进行简算，2.6×3÷2.6×3运用乘法的交换律、除法的性质进行简算．
解答 解：
| 30×0.5=15 | 0.78×0.2=0.156 | 340-127=213 |
| 10÷0.05=200 | 3.92+3.79=7.71 | 629-138=491 |
| 29.2-6.5=22.7 | 2.8-1.91=0.89 | 3.4×2=6.8 |
| 3.9×20=78 | 3.2+0.27=3.47 | 0.5×0.28=0.14 |
| 3.6÷0.02=180 | 24×9=216 | 2.5+5.6=8.1 |
| 0.8×0.9=0.72 | 1.5×8=12 | 2.8÷0.4=7 |
| 3.9-2.18=1.72 | 0.35×7=2.45 | 5.1÷1.7=3 |
| 720÷20=36 | 1.5×5=7.5 | 3.2÷4=0.8 |
| 2.6×4=10.4 | 8-0.125=7.875 | 72.6÷6=12.1 |
| 0.38+4.92=5.3 | 3.4×5=17 | 70.7÷7=10.1 |
| 3.8÷0.2=19 | 1.23+3.46=4.69 | 23.5-（3.5+6）=14 |
| 3.6×0.2=0.72 | 2.5×8=20 | 2.6×3÷2.6×3=9 |
| 3.18+0.43=3.61 | 1.2×25=30 | 25×2.4=60 |
| 4×0.25=1 | 6.5-0.8=5.7 | 33.9-2.5-7.5=23.9 |
| 1.4×0.7=0.98 | 5-2.1=2.9 | 7.25×4=29 |
| 3.18+2.78=5.96 | 3.75÷0.5=7.5 | 6.8÷0.25=27.2 |
| 6.24-0.38=5.86 | 3.14+5.7=8.84 | 170-25=145 |
| 3.4×0.7=2.38 | 3.28-1.8=1.48 | 162÷10=16.2 |
| 0.78-0.39=0.39 | 3.6×5=18 | 12.7-5+7.3=15 |
| 0.125×80=10 | 16.8÷21=0.8 | 1.9×40=76 |
点评 此题考查了整数、小数加减乘除法的口算能力，注意灵活运用运算定律进行简算．
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