Erbijsom en erafsom maken tot 20
In de mix
1.
15
12
–
=
2.
17
1
+
=
3.
13
4
+
=
4.
12
1
+
=
5.
12
3
+
=
6.
15
4
+
=
7.
20
18
–
=
8.
12
2
+
=
9.
15
5
+
=
10.
20
16
–
=
11.
14
13
–
=
12.
16
2
+
=
13.
15
1
+
=
14.
13
12
–
=
15.
20
17
–
=
16.
17
16
–
=
17.
12
2
+
=
18.
13
2
+
=
19.
17
3
+
=
20.
16
15
–
=
21.
18
16
–
=
22.
19
15
–
=
23.
14
13
–
=
24.
15
14
–
=