Another classic. Wonderful and beautiful piece of work. It is very hard to make programs that don´t just drill maths but teach concepts. Dragonbox succeed again. My son loves it. Oh and it doesn´t just teach long addition and substraction but the proper way of writing numbers. Extra bonus for my son who loves to write his numbers from the bottom. The program excepts these but also shows him the right way to do it. But ... we found a bug. When my son adding bees and the sum clearly showed 8 plus 2 in the first column it called out 8 plus 3! this is all the stranger as it still accepted 10 as the correct answer. Needs to be sorted out. Otherwise the game is great, really compelling.