Across
1
Closed shape with straight sides
4
Single numeral from 0 to 9
5
Distance from center to edge of circle
6
Sum divided by count
7
Lines that never intersect
11
Value that does not change
Down
2
Repeated addition
3
Number greater than zero
4
Number with digits after a point
8
Symbol representing unknown value
9
Three-sided polygon
10
Rectangular array of numbers