Across
1
Parts per hundred
3
Split into equal parts
4
Line crossing from corner to corner
6
Round shape with all points equidistant
8
Rectangle with four equal sides
9
Closed shape with straight sides
11
U-shaped curve of a quadratic function
12
Proven mathematical statement
Down
2
Part of a whole number
3
Single numeral from 0 to 9
5
Three-sided polygon
7
Math using letters for unknown values
10
Repeated addition