Across
1
Split into equal parts
3
Reference line in a graph
5
Single numeral from 0 to 9
7
Number greater than zero
8
U-shaped curve of a quadratic function
10
Space between two intersecting lines
11
Difference between highest and lowest values
Down
2
Total distance around a shape
3
Math using letters for unknown values
4
Mathematical statement of equality
6
Repeated addition
9
Symbol representing unknown value
12
Three-sided polygon