Geometry
Data
100
(Bill)

You might not want to eat it, but it is the circumference of a circle divided by its diameter.
What is pi?
100
(Toby)

It's the median of:
50, 61, 5, 75, 12, 20, 25
What is 25?
200
(Bill)

You could go to Egypt to see them, or you could draw your own using 5 points in 3D space, then connecting them.
What is a pyramid?
300
(Margaret)

It's a 2D shape with 9 sides, and the name starts and ends with an N
What is a nonogon?
400
(Weston)

It's a 12-sided 2D shape
What is a Dodecagon?