题目内容
| 计算下面各题.(能简算的要简算) (
|
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|
|
分析:(1)先算加法,再算除法;
(2)把除法改为乘法,利用乘法分配律简算;
(3)先算加法,再算减法,最后算除法;
(4)先算减法,再算乘法,最后算除法.
(2)把除法改为乘法,利用乘法分配律简算;
(3)先算加法,再算减法,最后算除法;
(4)先算减法,再算乘法,最后算除法.
解答:解:(1)(
+
)÷
=
×
=
;
(2)
×
+
÷
=
×
+
×
=(
+
)×
=1×
=
;
(3)
÷[
-(
+
)]
=
÷[
-
]
=
×3
=
;
(4)
÷[(1-
)×
]
=
÷[(
×
]
=
×
=
.
| 1 |
| 6 |
| 1 |
| 2 |
| 6 |
| 5 |
=
| 2 |
| 3 |
| 5 |
| 6 |
=
| 5 |
| 9 |
(2)
| 5 |
| 7 |
| 2 |
| 9 |
| 2 |
| 7 |
| 9 |
| 2 |
=
| 5 |
| 7 |
| 2 |
| 9 |
| 2 |
| 7 |
| 2 |
| 9 |
=(
| 5 |
| 7 |
| 2 |
| 7 |
| 2 |
| 9 |
=1×
| 2 |
| 9 |
=
| 2 |
| 9 |
(3)
| 5 |
| 18 |
| 5 |
| 6 |
| 1 |
| 6 |
| 1 |
| 3 |
=
| 5 |
| 18 |
| 5 |
| 6 |
| 1 |
| 2 |
=
| 5 |
| 18 |
=
| 5 |
| 6 |
(4)
| 1 |
| 4 |
| 1 |
| 4 |
| 6 |
| 5 |
=
| 1 |
| 4 |
| 3 |
| 4 |
| 6 |
| 5 |
=
| 1 |
| 4 |
| 10 |
| 9 |
=
| 5 |
| 18 |
点评:此题考查分数四则混合运算的计算方法,抓住运算顺序,根据数字特点灵活选用运算定律简算.
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