Very nice
I have several complaints.
First, straight-up math problems just don't do it for me, so I didn't really like that part.
Second, when you go to the block stage, it doesn't say not to count the blocks that aren't shaded. At first I counted them too because I thought that was just so that you could see the ones behind them. Obviously, this is not a big problem, since you realize it after your first mistake.
Lastly, at the end of the game, you go to a high score page where the high score is 0. Come on.