Across
1
Middle value in an ordered dataset
4
The number representing nothing
6
Number less than zero
9
U-shaped curve of a quadratic function
11
Amount of space an object occupies
12
Math using letters for unknown values
Down
2
Mathematical rule or equation
3
Split into equal parts
5
Rectangle with four equal sides
7
Repeated addition
8
Steepness of a line
10
Three-sided polygon
13
Total distance around a shape
14
Proven mathematical statement
15
Sum divided by count