题目内容
计算下面各题,能简算的要简算.
|
|
| ||||||||||||||||||
5-
|
|
|
分析:(1)(2)(3)(5)根据四则运算的计算顺序计算;
(4)根据减法的性质计算;
(6)根据加法交换律计算.
(4)根据减法的性质计算;
(6)根据加法交换律计算.
解答:解:(1)
-
+
,
=
-
+
,
=
;
(2)
-(
+
),
=
-
,
=
;
(3)
-(
-
),
=
-
,
=
;
(4)5-
-
,
=5-(
+
),
=5-1,
=4;
(5)
+(
-
),
=
+
,
=
;
(6)
+
+
,
=
+
+
,
=1
.
| 7 |
| 8 |
| 5 |
| 12 |
| 1 |
| 6 |
=
| 21 |
| 24 |
| 10 |
| 24 |
| 4 |
| 24 |
=
| 5 |
| 8 |
(2)
| 4 |
| 3 |
| 2 |
| 5 |
| 3 |
| 10 |
=
| 4 |
| 3 |
| 7 |
| 10 |
=
| 19 |
| 10 |
(3)
| 1 |
| 2 |
| 3 |
| 4 |
| 3 |
| 8 |
=
| 1 |
| 2 |
| 3 |
| 8 |
=
| 1 |
| 8 |
(4)5-
| 4 |
| 9 |
| 5 |
| 9 |
=5-(
| 4 |
| 9 |
| 5 |
| 9 |
=5-1,
=4;
(5)
| 2 |
| 3 |
| 1 |
| 2 |
| 1 |
| 4 |
=
| 2 |
| 3 |
| 1 |
| 4 |
=
| 11 |
| 12 |
(6)
| 2 |
| 5 |
| 1 |
| 3 |
| 3 |
| 5 |
=
| 2 |
| 5 |
| 3 |
| 5 |
| 1 |
| 3 |
=1
| 1 |
| 3 |
点评:本题主要考查了学生在分数四则运算中灵活运用简便算法的计算能力.
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