Across
1
Sum divided by count
3
Split into equal parts
4
Result of addition
5
Mathematical rule or equation
6
Line touching circle at one point
7
Divisible by two
Down
1
Space between two intersecting lines
2
Number divisible only by 1 and itself
3
Number with digits after a point
4
Collection of distinct elements
8
Longest side of a right triangle
9
Three-sided polygon