横向
1
Number greater than zero
5
Math using letters for unknown values
9
Difference between highest and lowest values
10
Repeated addition
12
Result of multiplication
纵向
2
Visual representation of data
3
Number divisible only by 1 and itself
4
Collection of distinct elements
6
Part of a whole number
7
Lines that never intersect
8
Round shape with all points equidistant
11
Longest side of a right triangle
13
Line touching circle at one point