Oefen erbijsommen en erafsommen tot 50
In de mix
1.
35
20
–
=
2.
15
10
+
=
3.
20
15
–
=
4.
20
15
+
=
5.
35
15
–
=
6.
25
20
+
=
7.
50
25
–
=
8.
20
15
–
=
9.
35
25
–
=
10.
25
20
–
=
11.
30
10
+
=
12.
25
15
–
=
13.
30
25
–
=
14.
30
5
+
=
15.
15
0
+
=
16.
30
15
–
=
17.
30
15
+
=
18.
25
20
+
=
19.
25
15
–
=
20.
35
30
–
=
21.
45
30
–
=
22.
15
25
+
=
23.
50
45
–
=
24.
45
30
–
=