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