Oefen erbijsommen en erafsommen tot 50
In de mix
1.
40
20
–
=
2.
40
10
+
=
3.
40
30
–
=
4.
15
5
+
=
5.
15
5
+
=
6.
15
5
+
=
7.
15
30
+
=
8.
30
25
–
=
9.
20
15
+
=
10.
40
15
–
=
11.
25
20
–
=
12.
40
35
–
=
13.
50
30
–
=
14.
30
15
–
=
15.
40
15
–
=
16.
25
10
+
=
17.
15
0
+
=
18.
10
5
+
=
19.
20
20
+
=
20.
35
25
–
=
21.
45
5
+
=
22.
45
20
–
=
23.
40
25
–
=
24.
10
5
+
=