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