Use of applied mathematics during hiring process for developers

What qualities does this task helps to demonstrate?

  1. problem solving and ability to make a problem simpler but get the correct answer
  2. Ability to save several seconds by not running calculator program
  3. p
  4. algebra skills
  5. how frequently the person uses pure math
  6. recognising patterns
  7. 8
  8. arithmetic (or maybe, 'quickk calculation')
  9. don't know
  10. Don't know