问题 解答题
用简便方法计算.
(1)
1
12
×5+
1
12
(2)
57
10
×
3
10
+
3
10
×
3
10
(3)
4
5
×8×
5
8
×
1
4
(4)24×(
3
8
+
3
4
答案

(1)

1
12
×5+
1
12

=

1
12
×(5+1),

=

1
12
×6,

=

1
2

(2)

57
10
×
3
10
+
3
10
×
3
10

=(

57
10
+
3
10
)×
3
10

=6×

3
10

=

9
5

=1

4
5

(3)

4
5
×8×
5
8
×
1
4

=(

4
5
×
1
4
)×(8×
5
8
),

=

1
5
×5,

=1;

(4)24×(

3
8
+
3
4
),

=24×

3
8
+24×
3
4

=9+18,

=27.

单项选择题
问答题 简答题