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