题目内容
脱式计算:
|
|
5-
| ||||||||||||||||
|
|
分析:(1)(2)按照从左到右的顺序计算;
(3)根据减法的性质简算;
(4)先算小括号里面的减法,再算括号外的加法;
(5)根据加法交换律和结合律简算.
(3)根据减法的性质简算;
(4)先算小括号里面的减法,再算括号外的加法;
(5)根据加法交换律和结合律简算.
解答:解:(1)
-
+
,
=
+
,
=
;
(2)
+
-
,
=
-
,
=
;
(3)5-
-
,
=5-(
+
),
=5-1,
=4;
(4)
+(
-
),
=
+
,
=
;
(5)
+
+
+
,
=(
+
)+(
+
),
=1+1,
=2.
5 |
6 |
3 |
4 |
2 |
3 |
=
1 |
12 |
2 |
3 |
=
3 |
4 |
(2)
3 |
8 |
1 |
2 |
1 |
4 |
=
7 |
8 |
1 |
4 |
=
5 |
8 |
(3)5-
4 |
7 |
3 |
7 |
=5-(
4 |
7 |
3 |
7 |
=5-1,
=4;
(4)
2 |
3 |
3 |
5 |
1 |
2 |
=
2 |
3 |
1 |
10 |
=
23 |
30 |
(5)
4 |
9 |
3 |
10 |
5 |
9 |
7 |
10 |
=(
4 |
9 |
5 |
9 |
3 |
10 |
7 |
10 |
=1+1,
=2.
点评:本题考查了分数加减法混合运算,注意运算顺序和运算法则,灵活运用所学的运算定律进行简便计算.
练习册系列答案
相关题目