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