20
-
15
=
____________________
15
-
11
=
____________________
20
-
7
=
____________________
14
-
9
=
____________________
15
-
13
=
____________________
12
-
7
=
____________________
16
-
6
=
____________________
13
-
8
=
____________________
17
-
6
=
____________________
11
-
9
=
2
