Across
1
Lines that never intersect
2
Single numeral from 0 to 9
4
Divisible by two
6
Space between two intersecting lines
7
System of ordered marks for measuring
9
Sum divided by count
10
Result of addition
Down
2
Split into equal parts
3
Repeated addition
5
Three-sided polygon
8
Collection of distinct elements
11
Rectangular array of numbers