题目内容
怎样算简便就怎样算.
|
4-
|
| ||||||||||||||||||||||||
|
|
|
分析:(1)乘除法同时脱式,再算减法;
(2)连减两个数,写成减去这两个数的和比较简便;
(3)用乘法分配律进行简算;
(4)用乘法交换、结合律进行简算;
(5)乘除法同时脱式,再算加法;
(6)先算小括号里的运算,再算中括号里的运算,最后算括号外面的运算.
(2)连减两个数,写成减去这两个数的和比较简便;
(3)用乘法分配律进行简算;
(4)用乘法交换、结合律进行简算;
(5)乘除法同时脱式,再算加法;
(6)先算小括号里的运算,再算中括号里的运算,最后算括号外面的运算.
解答:解:(1)
×
-
÷
,
=1-
,
=
;
(2)4-
-
,
=4-(
+
),
=2
;
(3)
×58+
×41+
,
=
×(58+41+1),
=
×100,
=12.5;
(4)
×
×
-
,
=
-
,
=
;
(5)
×
+
÷
,
=
+
,
=
;
(6)
÷[(
-
)÷
],
=
÷[
×
],
=
×5,
=4.
5 |
6 |
6 |
5 |
9 |
10 |
9 |
5 |
=1-
1 |
2 |
=
1 |
2 |
(2)4-
5 |
11 |
7 |
11 |
=4-(
5 |
11 |
7 |
11 |
=2
10 |
11 |
(3)
1 |
8 |
1 |
8 |
1 |
8 |
=
1 |
8 |
=
1 |
8 |
=12.5;
(4)
4 |
5 |
4 |
7 |
5 |
4 |
1 |
2 |
=
4 |
7 |
1 |
2 |
=
1 |
14 |
(5)
4 |
5 |
5 |
6 |
2 |
5 |
3 |
5 |
=
2 |
3 |
2 |
3 |
=
4 |
3 |
(6)
4 |
5 |
5 |
8 |
1 |
2 |
5 |
8 |
=
4 |
5 |
1 |
8 |
8 |
5 |
=
4 |
5 |
=4.
点评:此题考查分数的四则混合运算,能简算的用简便方法计算,不能简算的就按照运算顺序进行计算.
练习册系列答案
相关题目