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