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