number of sides
patterning
skip counting
100
circle
0 sides
100
XXooXXoo
AABB
100
10, 20, 30, 40,
50
200
triangle
3 Sides
200
+000+000
ABBB
200
5, 10, 15, 20,
25
300
square
4 sides
300
xxO+xxO+
AABC
300
2, 4, 6, 8,
10
400
rectangle
4 Sides
400
X+/=X+/=
ABCD
400
Which number is missing? 10, 20, ?, 40, 50
30
500
Pentagon
5 sides
500
+=+/+=+/
ABAC
500
Which number is missing? 5, 10, ?, 20, 25
15