Oefen erbijsommen en erafsommen tot 100
In de mix
1.
10
20
+
=
2.
50
20
+
=
3.
30
20
+
=
4.
70
30
–
=
5.
90
50
–
=
6.
70
50
–
=
7.
50
30
–
=
8.
30
40
+
=
9.
70
50
–
=
10.
90
70
–
=
11.
30
20
+
=
12.
90
70
–
=
13.
70
30
–
=
14.
50
30
–
=
15.
90
30
–
=
16.
70
50
–
=
17.
70
30
–
=
18.
70
30
–
=
19.
70
30
–
=
20.
90
50
–
=
21.
50
30
–
=
22.
70
20
+
=
23.
10
20
+
=
24.
50
20
+
=