横向
1
Sum divided by count
6
Total distance around a shape
7
The number representing nothing
9
Number that divides evenly into another
11
Exact correspondence on both sides
纵向
2
Lines that never intersect
3
Longest side of a right triangle
4
Middle value in an ordered dataset
5
Power to which a number is raised
8
Symbol representing unknown value
10
System of ordered marks for measuring
12
Repeated addition