横向
1
Single numeral from 0 to 9
4
Repeated addition
5
Parts per hundred
6
Divisible by two
10
Steepness of a line
11
Mathematical rule or equation
13
U-shaped curve of a quadratic function
纵向
2
Corner point of a polygon
3
Symbol representing unknown value
7
Comparison of two quantities
8
Part of a line with two endpoints
9
Mathematical statement of equality
12
Space between two intersecting lines