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