Enter a math problem for it to solve. You can see all of the functions and operators in the two lists. You can't put negative. Put (0-what ever your number is). If I wanted -16, I would put (0-16).
Thank you, MasterOfArithmetic for making the original project! Some things that I added: I slowed this down so you can see the stack list working. On start, the stack list and output variable are cleared.
