横向
1
Number greater than zero
4
U-shaped curve of a quadratic function
6
The number representing nothing
7
Part of a circle's circumference
9
Number with digits after a point
纵向
2
Number that divides evenly into another
3
Single numeral from 0 to 9
4
Lines that never intersect
5
Round shape with all points equidistant
8
System of ordered marks for measuring