题目内容
(1)
×
×7
=
×7×
=2×
=
(2)
×9+
=
×(9+1)
=
×10
=7
| 2 |
| 7 |
| 3 |
| 8 |
=
| 2 |
| 7 |
| 3 |
| 8 |
=2×
| 3 |
| 8 |
=
| 3 |
| 4 |
√
√
(2)
| 7 |
| 10 |
| 7 |
| 10 |
=
| 7 |
| 10 |
=
| 7 |
| 10 |
=7
√
√
.分析:(1)根据乘法交换律进行简算;
(2)根据乘法分配律进行简算.
(2)根据乘法分配律进行简算.
解答:解:
(1)
×
×7,
=
×7×
,
=2×
,
=
;
(2)
×9+
,
=
×(9+1),
=
×10,
=7.
故答案为:√,√.
(1)
| 2 |
| 7 |
| 3 |
| 8 |
=
| 2 |
| 7 |
| 3 |
| 8 |
=2×
| 3 |
| 8 |
=
| 3 |
| 4 |
(2)
| 7 |
| 10 |
| 7 |
| 10 |
=
| 7 |
| 10 |
=
| 7 |
| 10 |
=7.
故答案为:√,√.
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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