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