+ and - integers

Edit Answers
123456789
Across
  1. 1. 6x9=54
  2. 4. 899-99-5+4+1=800
  3. 5. 11x55=605
  4. 6. 38x4=152
  5. 7. 9x4=36
  6. 9. 400+50+25+25+2=502
Down
  1. 2. 50--50=100
  2. 3. 400--50=450
  3. 6. 999+1=1000
  4. 8. 501--99=600