题目内容
| 用简便方法计算下面各题. 0.25×3.2×0.125 |
2.46×19-0.46×19 |
| 34.5×102 | 9.8×9.9+0.98. |
分析:①把3.2拆为0.4×8,运用乘法结合律计算即可.
②③④运用乘法分配律进行计算即可.
②③④运用乘法分配律进行计算即可.
解答:解:
④9.8×9.9+0.98
=0.98×99+0.98
=0.98×(99+1)
=98.
| ①0.25×3.2×0.125 =(0.25×0.4)×(8×0.125) =0.1×1 =0.1; ②2.46×19-0.46×19 =(2.46-0.46)×19 =2×19 =38; |
|
| ③34.5×102 =34.5×(100+2) =34.5×100+34.5×2 =3450+69 =3519; |
=0.98×99+0.98
=0.98×(99+1)
=98.
点评:完成本题要注意分析式中数据,运用合适的简便方法计算.
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