Across
1
Number less than zero
6
Rectangle with four equal sides
8
Divisible by two
10
Round shape with all points equidistant
11
Line segment connecting two circle points
Down
2
Single numeral from 0 to 9
3
Line touching circle at one point
4
Steepness of a line
5
Proven mathematical statement
7
Amount of space an object occupies
9
Number with digits after a point
12
The number representing nothing
13
Part of a whole number