Snelle erbijsommen en erafsommen tot 20
In de mix
1.
20
19
–
=
2.
12
1
+
=
3.
14
1
+
=
4.
15
12
–
=
5.
15
14
–
=
6.
12
2
+
=
7.
14
1
+
=
8.
13
6
+
=
9.
19
18
–
=
10.
20
13
–
=
11.
19
12
–
=
12.
18
17
–
=
13.
13
12
–
=
14.
14
12
–
=
15.
12
4
+
=
16.
18
14
–
=
17.
17
13
–
=
18.
16
14
–
=
19.
12
0
+
=
20.
15
14
–
=
21.
15
13
–
=
22.
14
13
–
=
23.
13
2
+
=
24.
19
12
–
=