题目内容
计算下面各题,能简算的要简算.
|
|
|
分析:(1)按照从左向右的顺序进行计算;
(2)根据加法交换律和结合律进行简算;
(3)先算小括号里面的加法,再算括号外面的加法.
(2)根据加法交换律和结合律进行简算;
(3)先算小括号里面的加法,再算括号外面的加法.
解答:解:(1)
-
+1,
=
+1,
=1
;
(2)
+
+
+
,
=(
+
)+(
+
),
=1+
,
=1
;
(3)
+(
+
).
=
+
,
=
.
| 5 |
| 13 |
| 2 |
| 13 |
=
| 3 |
| 13 |
=1
| 3 |
| 13 |
(2)
| 3 |
| 8 |
| 2 |
| 9 |
| 5 |
| 9 |
| 5 |
| 8 |
=(
| 3 |
| 8 |
| 5 |
| 8 |
| 2 |
| 9 |
| 5 |
| 9 |
=1+
| 7 |
| 9 |
=1
| 7 |
| 9 |
(3)
| 1 |
| 3 |
| 1 |
| 4 |
| 3 |
| 8 |
=
| 1 |
| 3 |
| 5 |
| 8 |
=
| 23 |
| 24 |
点评:根据题意,先弄清运算顺序,然后再进一步计算即可;能简算的要简算.
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