Numbers

12345678
Across
  1. 1. 2 + 4
  2. 2. 3 + 2
  3. 3. 9 + 1
  4. 4. the first number
  5. 8. 1 + 2
Down
  1. 1. 4 + 3
  2. 3. 1 + 1
  3. 5. 5 + 3
  4. 6. 2 + 2
  5. 7. 5 + 4