题目内容

下面各题怎样算简便就怎样算.
(1)
4
9
×
9
14
÷
4
21
  
(2)0.8+
1
2
÷
5
6
(3)(
4
7
+
3
8
)×56
(4)
3
8
+
4
7
+
1
4
×
2
5
(5)(0.25+
1
3
)×(1.6÷
4
5
)
(6)
3
4
×[1÷(
5
6
+
3
4
)]
分析:(3)运用乘法分配律简算,其余题目按照先算乘除,再算加减,有括号的先算括号里面的顺序计算.
解答:解:(1)
4
9
×
9
14
÷
4
21

=
4
9
×
9
14
×
21
4

=
3
2


(2)0.8+
1
2
÷
5
6

=0.8+0.6,
=1.4;

(3)(
4
7
+
3
8
)×56

=56×
4
7
+
3
8
×56,
=32+21,
=53;

(4)
3
8
+
4
7
+
1
4
×
2
5

=
3
8
+
4
7
+
1
10

=
53
56
+
1
10

=
293
280


(5)(0.25+
1
3
)×(1.6÷
4
5
)

=
7
12
×2,
=
7
6


(6)
3
4
×[1÷(
5
6
+
3
4
)]

=
3
4
×(1÷
19
12
),
=
3
4
×
12
19

=
9
19
点评:乘法分配律是常用的简算方法,要灵活运用.
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