Across
1
Line crossing from corner to corner
6
Parts per hundred
7
Math using letters for unknown values
8
Single numeral from 0 to 9
9
Mathematical rule or equation
11
Exact correspondence on both sides
12
Mathematical statement of equality
Down
2
Part of a circle's circumference
3
Number less than zero
4
Comparison of two quantities
5
Amount of space an object occupies
10
Part of a line with two endpoints
13
Reference line in a graph