Across
1
Difference between highest and lowest values
4
Amount of space an object occupies
6
Power to which a number is raised
7
Part of a circle's circumference
8
Distance from center to edge of circle
Down
2
Single numeral from 0 to 9
3
Number divisible only by 1 and itself
5
Number less than zero
9
The number representing nothing
10
Math using letters for unknown values
11
Divisible by two