Across
1
Value that does not change
4
Lines that never intersect
5
Exact correspondence on both sides
6
Single numeral from 0 to 9
7
Three-sided polygon
8
Symbol representing unknown value
9
Comparison of two quantities
11
System of ordered marks for measuring
Down
2
Number that divides evenly into another
3
Number greater than zero
4
Parts per hundred
10
Corner point of a polygon
12
Repeated addition