Across
1
Exact correspondence on both sides
4
U-shaped curve of a quadratic function
5
Round shape with all points equidistant
9
Space between two intersecting lines
10
Symbol representing unknown value
Down
1
Collection of distinct elements
2
Single numeral from 0 to 9
3
Middle value in an ordered dataset
6
Three-sided polygon
7
Number with digits after a point
8
Math using letters for unknown values