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