Oefen erbijsommen en erafsommen tot 50
In de mix
1.
20
15
–
=
2.
10
5
+
=
3.
20
20
+
=
4.
20
5
+
=
5.
50
35
–
=
6.
20
15
–
=
7.
35
15
–
=
8.
30
25
–
=
9.
45
25
–
=
10.
40
10
+
=
11.
20
15
–
=
12.
30
5
+
=
13.
50
40
–
=
14.
40
20
–
=
15.
15
10
+
=
16.
20
15
–
=
17.
45
20
–
=
18.
20
20
+
=
19.
35
25
–
=
20.
50
25
–
=
21.
30
15
–
=
22.
15
30
+
=
23.
15
5
+
=
24.
40
5
+
=