题目内容
脱式计算.
(1)
|
(2)
|
(3)
|
分析:(1)根据加法交换律进行计算;
(2)先算小括号里面的减法,再算括号外面的减法;
(3)根据连减的性质进行计算.
(2)先算小括号里面的减法,再算括号外面的减法;
(3)根据连减的性质进行计算.
解答:解:(1)
+
+
,
=
+
+
,
=1+
,
=1
;
(2)
-(
-
),
=
-
,
=
;
(3)
-
-
,
=
-(
+
),
=
-1,
=
.
| 4 |
| 9 |
| 6 |
| 7 |
| 5 |
| 9 |
=
| 4 |
| 9 |
| 5 |
| 9 |
| 6 |
| 7 |
=1+
| 6 |
| 7 |
=1
| 6 |
| 7 |
(2)
| 3 |
| 4 |
| 5 |
| 6 |
| 1 |
| 3 |
=
| 3 |
| 4 |
| 1 |
| 2 |
=
| 1 |
| 4 |
(3)
| 5 |
| 3 |
| 2 |
| 7 |
| 5 |
| 7 |
=
| 5 |
| 3 |
| 2 |
| 7 |
| 5 |
| 7 |
=
| 5 |
| 3 |
=
| 2 |
| 3 |
点评:分数四则运算,先弄清运算顺序,然后再进行计算,能简算的要简算.
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