Across
1
Difference between highest and lowest values
4
Amount of space an object occupies
5
Symbol representing unknown value
8
Rectangle with four equal sides
10
Parts per hundred
11
Power to which a number is raised
Down
2
Steepness of a line
3
Proven mathematical statement
6
Space between two intersecting lines
7
Part of a circle's circumference
9
The number representing nothing
12
Reference line in a graph
13
Split into equal parts