Across
1
Steepness of a line
5
Repeated addition
6
Divisible by two
8
Number less than zero
9
Symbol representing unknown value
10
Value that does not change
Down
1
Rectangle with four equal sides
2
Number with digits after a point
3
Number divisible only by 1 and itself
4
Split into equal parts
7
Math using letters for unknown values
11
The number representing nothing