题目内容
简便计算
1
|
|
|
|
|
考点:分数的简便计算
专题:运算顺序及法则
分析:(1)根据加法交换律简算;
(2)根据加法结合律简算;
(3)根据减法的性质简算;
(4)根据加法交换律和结合律简算;
(5)根据加法交换律简算.
(2)根据加法结合律简算;
(3)根据减法的性质简算;
(4)根据加法交换律和结合律简算;
(5)根据加法交换律简算.
解答:
解:(1)1
-1
+0.75
=1
+0.75-1
=2-1
=
;
(2)
+
+
=
+(
+
)
=
+
=
;
(3)
-
-
=
-(
-
)
=
-
=
;
(4)
+
-
+
=(
-
)+(
+
)
=
+1
=1
;
(5)
+
-
=
-
+
=
+
=
| 1 |
| 4 |
| 3 |
| 10 |
=1
| 1 |
| 4 |
| 3 |
| 10 |
=2-1
| 3 |
| 10 |
=
| 7 |
| 10 |
(2)
| 7 |
| 8 |
| 1 |
| 16 |
| 5 |
| 16 |
=
| 7 |
| 8 |
| 1 |
| 16 |
| 5 |
| 16 |
=
| 7 |
| 8 |
| 3 |
| 8 |
=
| 5 |
| 4 |
(3)
| 7 |
| 10 |
| 3 |
| 8 |
| 1 |
| 8 |
=
| 7 |
| 10 |
| 3 |
| 8 |
| 1 |
| 8 |
=
| 7 |
| 10 |
| 1 |
| 2 |
=
| 1 |
| 5 |
(4)
| 5 |
| 8 |
| 9 |
| 17 |
| 3 |
| 8 |
| 8 |
| 17 |
=(
| 5 |
| 8 |
| 3 |
| 8 |
| 9 |
| 17 |
| 8 |
| 17 |
=
| 1 |
| 4 |
=1
| 1 |
| 4 |
(5)
| 2 |
| 3 |
| 3 |
| 4 |
| 5 |
| 9 |
=
| 2 |
| 3 |
| 5 |
| 9 |
| 3 |
| 4 |
=
| 1 |
| 9 |
| 3 |
| 4 |
=
| 31 |
| 36 |
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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