Across
1
The number representing nothing
4
Steepness of a line
5
Three-sided polygon
6
Result of addition
7
Symbol representing unknown value
10
Closed shape with straight sides
11
Mathematical statement of equality
13
Line crossing from corner to corner
Down
2
Amount of space an object occupies
3
Difference between highest and lowest values
8
Power to which a number is raised
9
Number that divides evenly into another
12
Divisible by two