题目内容
脱式计算.(能简算的要简算)
+
+
+
+
-(
+
).
| 1 |
| 2 |
| 1 |
| 3 |
| 1 |
| 5 |
| 4 |
| 9 |
| 1 |
| 3 |
| 5 |
| 9 |
| 7 |
| 9 |
| 1 |
| 3 |
| 1 |
| 6 |
分析:(1)从左往右按顺序计算;
(2)根据加法交换率和结合律进行简算;
(3)先算括号里面的加法,再算括号外面的减法.
(2)根据加法交换率和结合律进行简算;
(3)先算括号里面的加法,再算括号外面的减法.
解答:解:(1)
+
+
,
=
+
,
=
;
(2)
+
+
,
=(
+
)+
,
=1
;
(3)
-(
+
),
=
-
,
=
.
| 1 |
| 2 |
| 1 |
| 3 |
| 1 |
| 5 |
=
| 5 |
| 6 |
| 1 |
| 5 |
=
| 31 |
| 30 |
(2)
| 4 |
| 9 |
| 1 |
| 3 |
| 5 |
| 9 |
=(
| 4 |
| 9 |
| 5 |
| 9 |
| 1 |
| 3 |
=1
| 1 |
| 3 |
(3)
| 7 |
| 9 |
| 1 |
| 3 |
| 1 |
| 6 |
=
| 7 |
| 9 |
| 1 |
| 2 |
=
| 5 |
| 18 |
点评:此题考查分数加减法的混合运算,根据数据的特点,按照运算顺序或运算定律进行计算即可.
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