Across
1
Rectangular array of numbers
3
Divisible by two
6
Single numeral from 0 to 9
7
Line touching circle at one point
10
Steepness of a line
11
Symbol representing unknown value
12
System of ordered marks for measuring
Down
2
Part of a whole number
4
Reference line in a graph
5
Rectangle with four equal sides
8
Value that does not change
9
Number with digits after a point
13
Number greater than zero