Across
1
Exact correspondence on both sides
3
Split into equal parts
5
Number less than zero
6
Parts per hundred
9
Value that does not change
11
Part of a circle's circumference
12
Divisible by two
Down
2
Total distance around a shape
3
Single numeral from 0 to 9
4
Difference between highest and lowest values
7
System of ordered marks for measuring
8
Steepness of a line
10
Repeated addition