横向
1
Number divisible only by 1 and itself
3
Single numeral from 0 to 9
5
Longest side of a right triangle
6
Line crossing from corner to corner
7
Round shape with all points equidistant
8
Symbol representing unknown value
纵向
2
Distance from center to edge of circle
4
Sum divided by count
9
Space between two intersecting lines
10
Visual representation of data
11
The number representing nothing
12
Math using letters for unknown values
13
Number greater than zero
14
Result of raising a number to an exponent
15
System of ordered marks for measuring