I think someone could create a game about it , a game composed of story telling which as they progress they get to know more about different angles of bitcoin world which could be useful when they grew up 
Then if they got it, they will focus more on bitcoin than studying? Teaching bitcoin to a CHILD is not a good idea, even though its part of innovating with technology It may distract them for the endeavor that they may accomplished some day , bitcoin includes too technical transactions that a cjild may not absorb easily, you are wasting, good promotion wrong time ,is a wrong thing.