Across
1
Number less than zero
5
The number representing nothing
8
Distance from center to edge of circle
9
Single numeral from 0 to 9
11
Number that divides evenly into another
12
Total distance around a shape
Down
2
Corner point of a polygon
3
Amount of space an object occupies
4
Sum divided by count
6
Collection of distinct elements
7
Comparison of two quantities
10
Difference between highest and lowest values
13
Part of a circle's circumference