The school I am interning at (The Carroll School) is using this in their middle school math classes. Small class sizes typically (4-8 kids /  class), and it's a 1:1 school where every child has a laptop. But - it's working well for designated independent work time in the math classes I've observed- where each kid is asked to play the game for 15 minutes on their own. Kids have their own profiles- and there are several different math mini games they can play, each game focusing on different math skills. Each mini game involves different game mechanics and art styles. But all games involve using arithmetic skills and math concepts to solve problems that progress them in the game. Good performance gives the kids in-game credits/money that they can use to customize their in-gam avatar.