Math Crossword puzzle test

This printable crossword puzzle has 10 clues. Answers range from 4 to 13 letters long. This crossword is also available to download as a Microsoft Word document or a PDF.

When 2 or more edges intersect they form these.
Multiplying a number by itself.
The middle of the numbers.
An average of numbers.
The largest number minus the smallest number.
Whole numbers and their opposites.
The number that is the most used/shown.
One of two equal factors of a number.
Lines in the same plane that never intersect.
All positive integers (including zero).