Initial code setup with notes on primary required methods/functions and inputs/outputs.
Rough definition of input and function methods. Comments on pending issues/needs.
Minor edits to first-go of defining input and function methods. Tackling rest of methods next.
Playing with possible modifications to code. Moved get_user_values method into main code. Created recall_user_function method necessary (I think) for printing  user-requested equation for confirmation. Other minor changes. Nothing tested yet.
Tested and corrected previous commit version. Value inputs and equation confirmation prompt seem ok for now.
Pre-testing. Should have the bulk of the code. Revised the method for calculating result. Still need to figure out where best to use to_f on user values.
Tested last commit. Converted calcuated values to strings in puts for calculate_equation method. Seemingly no issues with floats as currently coded. Next step - work through user confirmation of requested calculation and  deal with invalid inputs.
Pre-testing. Added code to test for valid function inputs, to confirm equation before evaluating, and to prompt user to calcuate a new equation.
Made corrections after testing previous commit, but something funky going on with confirm method and while loops. Committing current changes before messing with anything else too much.
Created separate file for simple calculator program without confirmation method. Does still include repeat option.