题目内容
能简便的要简便计算.
+
+
-(
-
)
+
+
-
.
2 |
7 |
3 |
4 |
5 |
7 |
3 |
5 |
1 |
2 |
1 |
4 |
1 |
6 |
7 |
8 |
5 |
6 |
1 |
8 |
分析:(1)(3)运用加法交换律与结合律简算;
(2)先算括号内的,再算括号外的.
(2)先算括号内的,再算括号外的.
解答:解:(1)
+
+
=(
+
)+
=1+
=1
;
(2)
-(
-
)
=
-
=
;
(3)
+
+
-
=(
+
)+(
-
)
=1+
=1
.
2 |
7 |
3 |
4 |
5 |
7 |
=(
2 |
7 |
5 |
7 |
3 |
4 |
=1+
3 |
4 |
=1
3 |
4 |
(2)
3 |
5 |
1 |
2 |
1 |
4 |
=
3 |
5 |
1 |
4 |
=
7 |
20 |
(3)
1 |
6 |
7 |
8 |
5 |
6 |
1 |
8 |
=(
1 |
6 |
5 |
6 |
7 |
8 |
1 |
8 |
=1+
3 |
4 |
=1
3 |
4 |
点评:此题主要考查分数的四则混合运算的运算顺序和应用运算定律进行简便计算.
![](http://thumb2018.1010pic.com/images/loading.gif)
练习册系列答案
相关题目