Number Puzzle

12345678
Across
  1. 3. 18.7126+14.033
  2. 4. |-917/81|
  3. 7. (-5)(-4)(-20)
  4. 8. 1/4/by-3/8
Down
  1. 1. 21/by-7
  2. 2. 1/11asadecimal
  3. 5. 5/8-(-7/8)
  4. 6. 177-63
  5. 7. -6+(-4)