Cool answer — I'll be sure to remind it to you next time you post a question in the forums ^^
More seriously though, there is a lot involved here.
oneking there is the "mechanical part" (the expected result, according to available numbers or not) and the "GUI" part (the sprites moving around, sounds, etc...)
Go through a few tutorials first, they will help you get the hang of C2 and how to realize some of the UI aspect/structure of a game. Tutorials like Create a memory match game or Asteroid in less than 100 events should give you experience on that level, making it easier for you to reproduce that game.
I don't know exactly how chrisbrobs implemented the mechanics in it (is there some use of arrays or lists).
Any insights Chris ?
Nice production by the way, nice little maths game.