How does the Heroes mind reader game work?

On the season 1 DVD for Heroes, there is a mind reader game on disc 5. And it asks you to pick a number between 1 and 100, then add the two numbers comprising the number, and subtract that number from the first number. Then it correlates a Heroes character to the newest number you get, and at the end, the game finds your Heroes character. And it's right every time. How does this work?