题目内容
用简便方法计算下面各题.
| (
|
|
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考点:运算定律与简便运算
专题:运算定律及简算
分析:(1)可将式中的除法算式变为乘法算式后,根据乘法分配律计算.
(2)先算括号中的乘法,再算除法.
(3)可根据乘法分配律计算.
(4)可将59变为60-1后,根据乘法分配律计算.
(2)先算括号中的乘法,再算除法.
(3)可根据乘法分配律计算.
(4)可将59变为60-1后,根据乘法分配律计算.
解答:
解:(1)
÷7+
×
=
×
+
×
=(
+
)×
=
×
=
;
(2)(
×
)÷
=
÷
=1;
(3)
×20+
×22
=
×(20+22)
=
×42
=30;
(4)
×59
=
×(60-1)
=
×60-
=59-
=58
.
| 8 |
| 13 |
| 1 |
| 7 |
| 6 |
| 13 |
=
| 8 |
| 13 |
| 1 |
| 7 |
| 1 |
| 7 |
| 6 |
| 13 |
=(
| 8 |
| 13 |
| 6 |
| 13 |
| 1 |
| 7 |
=
| 14 |
| 13 |
| 1 |
| 7 |
=
| 2 |
| 13 |
(2)(
| 1 |
| 2 |
| 1 |
| 3 |
| 1 |
| 6 |
=
| 1 |
| 6 |
| 1 |
| 6 |
=1;
(3)
| 5 |
| 7 |
| 5 |
| 7 |
=
| 5 |
| 7 |
=
| 5 |
| 7 |
=30;
(4)
| 59 |
| 60 |
=
| 59 |
| 60 |
=
| 59 |
| 60 |
| 59 |
| 60 |
=59-
| 59 |
| 60 |
=58
| 1 |
| 60 |
点评:完成本题要注意分析式中数据的特点,然后运用合适的方法计算.
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