Across
1
Space between two intersecting lines
4
Steepness of a line
6
Number greater than zero
7
Power to which a number is raised
12
Middle value in an ordered dataset
13
Divisible by two
Down
2
Number divisible only by 1 and itself
3
Three-sided polygon
5
Single numeral from 0 to 9
8
Lines that never intersect
9
The number representing nothing
10
Sum divided by count
11
Number that divides evenly into another