Across
1
Middle value in an ordered dataset
4
Proven mathematical statement
5
Value that does not change
9
Number with digits after a point
12
The number representing nothing
Down
1
Repeated addition
2
System of ordered marks for measuring
3
Rectangle with four equal sides
6
Exact correspondence on both sides
7
Line crossing from corner to corner
8
Result of multiplication
10
Collection of distinct elements
11
Power to which a number is raised