This is a mind reading exercise, and it must be done by following/performing each instruction very carefully. After you finish the final instruction, write down your final number and draw a square around it. Then see if you can discover the underlying principle of the game.


  • Think of a 2-digit number between 10 and 99, inclusive.
    (example, 39)
  • Add the number’s two digits together to create a sub-total.
    (example, 3 + 9 = sub-total of 12)
  • Create a final-total by subtracting the sub-total from your 2-digit number.
    (example, 39 – 12 = final-total of 27)
  • Think about your final-total and click to continue.