Across
1
Line crossing from corner to corner
4
Single numeral from 0 to 9
6
Rectangular array of numbers
7
Proven mathematical statement
8
Divisible by two
11
Longest side of a right triangle
Down
2
Number greater than zero
3
Sum divided by count
5
Number less than zero
9
Line segment connecting two circle points
10
Math using letters for unknown values
12
System of ordered marks for measuring