Across
1
Value that does not change
5
Math using letters for unknown values
7
Space between two intersecting lines
8
Symbol representing unknown value
9
Three-sided polygon
12
Number with digits after a point
Down
2
Part of a circle's circumference
3
Exact correspondence on both sides
4
Difference between highest and lowest values
6
Power to which a number is raised
10
Number divisible only by 1 and itself
11
Repeated addition