Apparently, I'm not as good at basic maths as I thought I was.
Anyway, decent little educational game with enough visual style to actually interest older kids. Perhaps the game would benefit from a faster "Keyboard mode" which would allow the user to type their answer instead of manually pressing the buttons on PC. I can see this game being used in classes; although to which age group I am not so sure of.
As for the mobile market, this should be plenty good enough, although I am a little unsure of who the target audience actually is for the mobile aspect of this game as children and adults alike are far less likely to download a maths game willingly.
Overall, decently polished, and visually great.