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