Across
1
Part of a circle's circumference
3
Middle value in an ordered dataset
4
Difference between highest and lowest values
8
Amount of space an object occupies
9
The number representing nothing
10
Round shape with all points equidistant
11
Reference line in a graph
Down
2
Symbol representing unknown value
5
Distance from center to edge of circle
6
Number divisible only by 1 and itself
7
Value that does not change