The purpose of this program is to create an interface through which users can add, subtract, divide, and multiply two fractional numbers together. For this program to function, the user is prompted to enter the operation that is to be calculated in the format (a/b + c/d) on the keyboard, where the sign '+' can be replaced with either a '-', '*' or a '/' to perform the respective mathematical operation. The program then calculates the results from one of the following equations:
a/b + c/d = (a*d + b*c) / (b*d)
a/b - c/d = (a*d - b*c) / (b*d)
a/b * c/d = (a*c) / (b*d)
a/b / c/d = (a*d) / (b*c)
The divisor and the divident of the result are then assigned to two different variables, which are displayed on the screen as the result of the calculation.