题目内容

脱式计算
(1)
4
15
+
1
3
-
1
12
×6
(2)
7
9
÷
11
5
+
2
9
×
5
11

(3)(
5
12
+
1
6
-
7
12
)÷
1
7
×20;
(4)[4-(
3
4
-
3
8
)]×
4
29

(5)[2-(
1
4
+
3
8
)]÷
1
4

(6)(
7
15
×
5
14
-
1
7
)×21.
分析:(1)(3)(4)(5)(6)依据四则运算顺序:先算第二级运算,再算第一级运算,如果只含有同一级运算,按照从左到右顺序计算,有括号先算括号里面的顺序解答即可解答,
(2)运用乘法分配律解答.
解答:解:(1)
4
15
+
1
3
-
1
12
×6,
=
4
15
+
1
3
-
1
2

=
9
15
-
1
2

=
1
10


(2)
7
9
÷
11
5
+
2
9
×
5
11

=(
7
9
+
2
9
)×
5
11

=1×
5
11

=
5
11


(3)(
5
12
+
1
6
-
7
12
)÷
1
7
×20,
=(
7
12
-
7
12
)÷
1
7
×20,
=0÷
1
7
×20,
=0;

(4)[4-(
3
4
-
3
8
)]×
4
29

=[4-
3
8
4
29

=
29
8
×
4
29

=
1
2


(5)[2-(
1
4
+
3
8
)]÷
1
4

=[2-
5
8
1
4

=
11
8
÷
1
4

=
11
2


(6)(
7
15
×
5
14
-
1
7
)×21,
=(
1
6
-
1
7
)×21,
=
1
42
×21,
=
1
2
点评:(1)依据四则运算顺序正确进行计算,(2)运用乘法分配律正确解决问题,是本题考查知识点.
练习册系列答案
相关题目

违法和不良信息举报电话:027-86699610 举报邮箱:58377363@163.com

精英家教网