This isn't as good at teaching column addition as it might first appear. The world and characters are beautifully crafted, and if I were rating this for its entertainment value alone I'd give it 5 stars. But unfortunately my son did not properly understand how column addition and subtraction work even after mastering the game and sinking many hours into it. For a while he really seemed to be learning, but in fact he was just powering through the sums by following an easy routine and the game's prompts, but never needing to understand exactly what it was he was doing or why he was doing it. Sure this does lay a decent foundation for learning column addition later and feeling comfortable with it, but it would be more time-efficient simply to teach it the old fashioned way. I highly recommend all the other Dragonbox games, but I think this one needs a little fine tuning before it can be as educational as the rest.