Math bash!

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Across
  1. 2. you do not add you use
  2. 5. you use this can use this as long
  3. 7. half of a number
  4. 8. more of a half
Down
  1. 1. longer division
  2. 3. in a row
  3. 4. the opposite of subtraction
  4. 6. the opposite of addition