题目内容
计算
+
+
-
-
+
.
| 5 |
| 12 |
| 3 |
| 4 |
| 1 |
| 12 |
| 7 |
| 10 |
| 3 |
| 8 |
| 1 |
| 8 |
| 4 |
| 15 |
| 5 |
| 6 |
考点:分数的加法和减法
专题:运算顺序及法则
分析:(1)根据加法交换律进行简算;
(2)根据减法的性质进行简算;
(3)先通分,再计算.
(2)根据减法的性质进行简算;
(3)先通分,再计算.
解答:
解:(1)
+
+
=
+
+
=
+
=
;
(2)
-
-
=
-(
+
)
=
-
=
;
(3)
+
=
+
=
=
.
| 5 |
| 12 |
| 3 |
| 4 |
| 1 |
| 12 |
=
| 5 |
| 12 |
| 1 |
| 12 |
| 3 |
| 4 |
=
| 1 |
| 2 |
| 3 |
| 4 |
=
| 5 |
| 4 |
(2)
| 7 |
| 10 |
| 3 |
| 8 |
| 1 |
| 8 |
=
| 7 |
| 10 |
| 3 |
| 8 |
| 1 |
| 8 |
=
| 7 |
| 10 |
| 1 |
| 2 |
=
| 1 |
| 5 |
(3)
| 4 |
| 15 |
| 5 |
| 6 |
=
| 8 |
| 30 |
| 25 |
| 30 |
=
| 33 |
| 30 |
=
| 11 |
| 10 |
点评:考查了运算定律与简便运算,四则混合运算.注意运算顺序和运算法则,灵活运用所学的运算定律简便计算.
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