Across
1
Part of a line with two endpoints
5
Line crossing from corner to corner
6
Visual representation of data
7
Round shape with all points equidistant
8
Exact correspondence on both sides
10
Single numeral from 0 to 9
Down
2
Value that does not change
3
Difference between highest and lowest values
4
Number that divides evenly into another
9
Closed shape with straight sides
11
Longest side of a right triangle
12
Math using letters for unknown values
13
The number representing nothing