I was playing this with the assumption that if I used a division without exactly dividing the number I would die horribly, which made it a lot more interesting (often I added a little to get a big exact division). Would be nice to have a preview of what your current set of operators were going to do to the number if this was the case though.
Also, I think you should start with zero cards since I felt a bit overloaded with information at the start of the game. Completing a round could also take you straight to the shop, since there's no reason to not visit it.