Addition and Subtraction Puzzle

12345678910
Across
  1. 1. 8001-2165
  2. 5. 8454-3212
  3. 8. 5363+4264
  4. 10. 8490+4493
Down
  1. 2. 7259-4238
  2. 3. 5571-1602
  3. 4. 3305+1274
  4. 6. 4839-2769
  5. 7. 1723+6529
  6. 9. 5033+1820