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