题目内容
用你喜欢的方法算:
÷7+
×
-(
-
)
+
×
÷2
×(
+
)+
÷
(
+
)×
+
.
5 |
12 |
7 |
12 |
1 |
7 |
7 |
8 |
5 |
9 |
1 |
8 |
1 |
6 |
3 |
4 |
2 |
3 |
12 |
5 |
5 |
6 |
3 |
4 |
4 |
5 |
17 |
49 |
1 |
99 |
24 |
19 |
16 |
17 |
1 |
8 |
15 |
17 |
分析:(1)将算式中除以7改写成乘
,再利用乘法分配律进行计算即可;
(2)把算式中的括号去掉,算式就转化成
-
+
,可先计算
+
,结果不变;
(3)按照分数的四则运算法则进行计算即可;
(4)按照乘法分配律进行计算即可;
(5)先将除以
转化成乘以99,再将99分成“49+49+1”,最后利用乘法分配律进行计算即可.
(6)直接利用乘法分配律进行计算即可.
1 |
7 |
(2)把算式中的括号去掉,算式就转化成
7 |
8 |
5 |
9 |
1 |
8 |
7 |
8 |
1 |
8 |
(3)按照分数的四则运算法则进行计算即可;
(4)按照乘法分配律进行计算即可;
(5)先将除以
1 |
99 |
(6)直接利用乘法分配律进行计算即可.
解答:解:(1)
÷7+
×
=
×
+
×
=(
+
)×
=1×
=
;
(2)
-(
-
)
=
+
-
=1-
=
;
(3)
+
×
÷2
=
+
÷2
=
+
=
;
(4)
×(
+
)+
=
×
+
=
+
=4
;
(5)
÷
=
×99
=
×(98+1)
=
×98+
×1
=34+
=34
;
(6)(
+
)×
+
=
×
+
×
+
=
+
+
=1
.
5 |
12 |
7 |
12 |
1 |
7 |
=
5 |
12 |
1 |
7 |
7 |
12 |
1 |
7 |
=(
5 |
12 |
7 |
12 |
1 |
7 |
=1×
1 |
7 |
=
1 |
7 |
(2)
7 |
8 |
5 |
9 |
1 |
8 |
=
7 |
8 |
1 |
8 |
5 |
9 |
=1-
5 |
9 |
=
4 |
9 |
(3)
1 |
6 |
3 |
4 |
2 |
3 |
=
1 |
6 |
1 |
2 |
=
1 |
6 |
1 |
4 |
=
5 |
12 |
(4)
12 |
5 |
5 |
6 |
3 |
4 |
4 |
5 |
=
12 |
5 |
19 |
12 |
4 |
5 |
=
19 |
5 |
4 |
5 |
=4
3 |
5 |
(5)
17 |
49 |
1 |
99 |
=
17 |
49 |
=
17 |
49 |
=
17 |
49 |
17 |
49 |
=34+
17 |
49 |
=34
17 |
49 |
(6)(
24 |
19 |
16 |
17 |
1 |
8 |
15 |
17 |
=
24 |
19 |
1 |
8 |
16 |
17 |
1 |
8 |
15 |
17 |
=
3 |
19 |
2 |
17 |
15 |
17 |
=1
3 |
19 |
点评:此题主要考查的是分数的四则混合运算和分数的简便运算.
练习册系列答案
相关题目