问题 解答题
用简便方法计算.
5
16
+
1
3
+
3
16
5
12
-
2
5
+
7
12
7
8
-( 
3
8
+
1
3
答案

(1)

5
16
+
1
3
+
3
16

=

5
16
+
3
16
+
1
3

=

1
2
+
1
3

=

5
6

(2)

5
12
-
2
5
+
7
12

=

5
12
+
7
12
-
2
5

=1-

2
5

=

3
5

(3)

7
8
-( 
3
8
+
1
3

=

7
8
-
3
8
-
1
3

=

1
2
-
1
3

=

1
6

单项选择题
选择题