Across
1
Result of addition
3
U-shaped curve of a quadratic function
4
Middle value in an ordered dataset
5
Single numeral from 0 to 9
7
Reference line in a graph
12
Mathematical statement of equality
Down
1
Collection of distinct elements
2
Exact correspondence on both sides
6
Mathematical rule or equation
8
Part of a line with two endpoints
9
Corner point of a polygon
10
Round shape with all points equidistant
11
Sum divided by count