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