Write a OOPCalculator class, by giving it proper states and behaviors. For example, you can have menuChoice, firstFloat, secondFloat as member variables. You can give it behaviors like, askCalcChoice, askTwoValues, displayResults to get the choice from users, to get the numbers and display the calculation results respectively. All of the code written for calculation needs to be properly placed within these methods of the OOPCalculator class. For example: askCalcChoice first displays the menu, prompts the user to input the choice, and then waits until user presses enter. Once a valid input is entered, it returns the choice (between 1 to 5 or A for addition, S for subtraction, M for multiplication, D for division or X for exit). Similarly, other methods will implement rest of the behaviors. The users of your OOPCaluclator class do not need to know internal details of how you have implemented your behaviors. These are the only public interface exposed to the users, rest of the details stays with OOPCalculator class.