题目内容
用自己喜欢的方法计算
+
+
=
+
+
+
=
-
-
=
-(
+
)=
| 8 |
| 15 |
| 6 |
| 7 |
| 7 |
| 15 |
| 5 |
| 13 |
| 5 |
| 6 |
| 8 |
| 13 |
| 1 |
| 6 |
| 7 |
| 10 |
| 3 |
| 8 |
| 1 |
| 8 |
| 11 |
| 12 |
| 1 |
| 12 |
| 1 |
| 6 |
分析:(1)根据加法交换律简算;
(2)根据加法交换律和结合律简算;
(3)(4)根据减法的性质简算.
(2)根据加法交换律和结合律简算;
(3)(4)根据减法的性质简算.
解答:解:(1)
+
+
=
+
+
=1+
=1
;
(2)
+
+
+
=(
+
)+(
+
)
=1+1
=2;
(3)
-
-
=
-(
+
)
=
-
=
;
(4)
-(
+
)
=
-
-
=
-
=
.
| 8 |
| 15 |
| 6 |
| 7 |
| 7 |
| 15 |
=
| 8 |
| 15 |
| 7 |
| 15 |
| 6 |
| 7 |
=1+
| 6 |
| 7 |
=1
| 6 |
| 7 |
(2)
| 5 |
| 13 |
| 5 |
| 6 |
| 8 |
| 13 |
| 1 |
| 6 |
=(
| 5 |
| 13 |
| 8 |
| 13 |
| 5 |
| 6 |
| 1 |
| 6 |
=1+1
=2;
(3)
| 7 |
| 10 |
| 3 |
| 8 |
| 1 |
| 8 |
=
| 7 |
| 10 |
| 3 |
| 8 |
| 1 |
| 8 |
=
| 7 |
| 10 |
| 1 |
| 2 |
=
| 1 |
| 5 |
(4)
| 11 |
| 12 |
| 1 |
| 12 |
| 1 |
| 6 |
=
| 11 |
| 12 |
| 1 |
| 12 |
| 1 |
| 6 |
=
| 5 |
| 6 |
| 1 |
| 6 |
=
| 2 |
| 3 |
点评:本题考查了基本的分数的加减混合运算,要注意分析数据,选择合适的简算方法简算.
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