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