题目内容
能简算的要简算
|
5-
|
| ||||||||||||||||||
|
|
7-(
|
考点:分数的简便计算,分数的四则混合运算
专题:运算顺序及法则,运算定律及简算
分析:(1)运用加法交换律与结合律简算.
(2)运用减法的性质简算.
(3)(4)通分计算.
(5)(6)先算括号内的,再算括号外的.
(2)运用减法的性质简算.
(3)(4)通分计算.
(5)(6)先算括号内的,再算括号外的.
解答:
解:(1)
+
+
+
=(
+
)+(
+
)
=1+1
=2
(2)5-
-
=5-(
+
)
=5-1
=4
(3)
-
+
=
-
+
=
(4)
-
+
=
-
+
=
(5)
+(
+
)
=
+
=
(5)7-(
-
)
=7-
=6
| 11 |
| 12 |
| 5 |
| 8 |
| 3 |
| 8 |
| 1 |
| 12 |
=(
| 11 |
| 12 |
| 1 |
| 12 |
| 5 |
| 8 |
| 3 |
| 8 |
=1+1
=2
(2)5-
| 3 |
| 7 |
| 4 |
| 7 |
=5-(
| 3 |
| 7 |
| 4 |
| 7 |
=5-1
=4
(3)
| 3 |
| 4 |
| 5 |
| 12 |
| 1 |
| 6 |
=
| 9 |
| 12 |
| 5 |
| 12 |
| 2 |
| 12 |
=
| 1 |
| 2 |
(4)
| 5 |
| 6 |
| 1 |
| 4 |
| 1 |
| 3 |
=
| 10 |
| 12 |
| 3 |
| 12 |
| 4 |
| 12 |
=
| 11 |
| 12 |
(5)
| 23 |
| 28 |
| 13 |
| 14 |
| 2 |
| 7 |
=
| 23 |
| 28 |
| 17 |
| 14 |
=
| 57 |
| 28 |
(5)7-(
| 3 |
| 4 |
| 2 |
| 5 |
=7-
| 7 |
| 20 |
=6
| 13 |
| 20 |
点评:此题主要考查分数的四则混合运算的运算顺序和应用运算定律进行简便计算.
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