Recreate this Calculator class in your own text editor and try passing in a string as an argument to the double method instead of an actual number. What happens and why?
Add a method to the Calculator class that will return the square of any number.
Create a new class called StringModifier.
Then, add a method to the StringModifier class called “make_uppercase” that will accept a string as a parameter and return a new string that is an all uppercase version of the original string.