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