Across
1
Number less than zero
5
Corner point of a polygon
6
Steepness of a line
7
Result of addition
8
Line touching circle at one point
9
Repeated addition
10
Difference between highest and lowest values
12
Number that divides evenly into another
Down
2
Number greater than zero
3
Part of a whole number
4
Math using letters for unknown values
11
The number representing nothing