Across
1
Mathematical rule or equation
4
Line touching circle at one point
8
Reference line in a graph
9
Steepness of a line
Down
2
Corner point of a polygon
3
Difference between highest and lowest values
5
Math using letters for unknown values
6
Repeated addition
7
Single numeral from 0 to 9
10
Middle value in an ordered dataset
11
Three-sided polygon