number play

123456789
Across
  1. 3. not exact
  2. 5. maths in mind calculations
  3. 6. number 6174
  4. 8. not exact
  5. 9. line patterns
Down
  1. 1. conjucture odd and even
  2. 2. sum adding digits of no
  3. 4. gretest number
  4. 7. number left to right same