Across
1
Part of a line with two endpoints
5
Steepness of a line
6
Sum divided by count
7
Single numeral from 0 to 9
9
Rectangle with four equal sides
10
Rectangular array of numbers
11
U-shaped curve of a quadratic function
Down
2
Number with digits after a point
3
Symbol representing unknown value
4
Part of a whole number
8
Mathematical statement of equality
12
Proven mathematical statement