题目内容
计算:
(1)4
+1
=
(2)5
-1
=
(1)4
| 2 |
| 3 |
| 3 |
| 4 |
6
| 5 |
| 12 |
6
;| 5 |
| 12 |
(2)5
| 1 |
| 6 |
| 5 |
| 6 |
3
| 1 |
| 3 |
3
.| 1 |
| 3 |
分析:(1)把4
看作4+
,1
看作1+
,再根据加法交换律和结合律进行计算;
(2)把5
看作5+
,1
看作1+
,然后再根据加法交换律和结合律进行计算.
| 2 |
| 3 |
| 2 |
| 3 |
| 3 |
| 4 |
| 3 |
| 4 |
(2)把5
| 1 |
| 6 |
| 1 |
| 6 |
| 5 |
| 6 |
| 5 |
| 6 |
解答:解:
(1)4
+1
,
=(4+
)+(1+
),
=(4+1)+(
+
),
=5+1
,
=6
,
(2)5
-1
,
=(5+
)-(1+
),
=(5-1)-(
-
),
=4-
,
=3
.
故答案为:6
,3
.
(1)4
| 2 |
| 3 |
| 3 |
| 4 |
=(4+
| 2 |
| 3 |
| 3 |
| 4 |
=(4+1)+(
| 2 |
| 3 |
| 3 |
| 4 |
=5+1
| 5 |
| 12 |
=6
| 5 |
| 12 |
(2)5
| 1 |
| 6 |
| 5 |
| 6 |
=(5+
| 1 |
| 6 |
| 5 |
| 6 |
=(5-1)-(
| 5 |
| 6 |
| 1 |
| 6 |
=4-
| 2 |
| 3 |
=3
| 1 |
| 3 |
故答案为:6
| 5 |
| 12 |
| 1 |
| 3 |
点评:带分数相加减,把带分数看作整数加分数的形式,再选择合适的运算定律进行计算.
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