Program takes in variable non exact.

[CH3791]

When I use my custom functions, I must put my equation into quotation marks if I want it to stay exact. This happens even if my CAS settings are "exact". For example:
Quotation Marks vs No Quotation Marks

Is there a way on the program side to not have this happen? I don't want to be doing an exam and have to go through yet another step in solving the questions.

Thanks in advance.