Wow, controls and UI are extremely polished and juicy! I love it!! I hope the controls to be a bit more forgiving, though (might be some resolution problem, but I feel like they could've been snap to the blank.. better? I think?)
I enjoyed the puzzles, especially 9 one (it was beautiful), and I think you had intended solutions (judging by the hints) (they seem clever, though!) but unforturnatly 8,7,6,5,2 can be beaten easily by n-m÷m or its minor variations. And to me, 4, 3 had too many elements and felt a bit tiring to solve. I think this has a potential to be an amazing puzzle game if you can prevent unintended solution and lead players to the right difficulty curve!!
