Across
1
The number representing nothing
3
Symbol representing unknown value
4
Proven mathematical statement
8
Number that divides evenly into another
9
Difference between highest and lowest values
10
Amount of space an object occupies
11
Closed shape with straight sides
12
Distance from center to edge of circle
13
Part of a line with two endpoints
Down
2
Mathematical statement of equality
5
Comparison of two quantities
6
U-shaped curve of a quadratic function
7
Parts per hundred