Crossword game about Math!

123456789
Across
  1. 2. To remove an amount from another
  2. 5. Addition. To add numbers together.
  3. 8. The answer to a subtraction equation
  4. 9. The inside space within a 2D shape
Down
  1. 1. The answer to an addition equation
  2. 3. Make the expression easier to look a
  3. 4. A unit of measurement for angles
  4. 5. The length of the outside of a 2D shape
  5. 6. Find the answer to the problem
  6. 7. The answer to a multiplication equation
  7. 9. The space between two lines that intersect