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