Math Escape Room Crossword Puzzle

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Across
  1. 5. the distance around an area
  2. 6. calculating a total of two or more numbers
  3. 7. this shape
  4. 8. an amount of surface covered
Down
  1. 1. to take away one number from another
  2. 2. a number that is close to the exact number
  3. 3. this shape has four equal sides
  4. 4. separated into parts