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