Well done!
Unfortunately I havn't really had the possibility to use my computer much these last two weeks and the game doesn't work on the phone. I have been able to watch Yanni and Zach play though.
The game looks really nice. Making good edutainment games is difficult but you might be on to something here.
On a small screen it isn't super obvious if you answer correctly. I would have wanted more obvious visual feedback right be the equation on an incorrect answer.