1. Think of any two digit number (say 39)
  2. Formulate the reverse of the two digit number (say 93 for 39)
  3. Find the difference of the larger of the two and the smaller of the two (say 93-39)
  4. Remember the picture indexed by the number in the previous step (here picture at 93 - 39 = 54).
  5. Hit Next! and be amazed