Across
1
Split into equal parts
3
Part of a circle's circumference
5
Part of a line with two endpoints
6
Math using letters for unknown values
7
Number less than zero
8
Value that does not change
11
Single numeral from 0 to 9
Down
2
Sum divided by count
4
Three-sided polygon
8
Round shape with all points equidistant
9
Difference between highest and lowest values
10
Number with digits after a point