Please i need an understanding on this:

Please i need an understanding on this:

Assume that you have just been given an assignment to develop a Python program that will act as a calculator. The calculator must prompt the user to enter two numbers and an operation. The operation can be to add, subtract, multiply, or divide the two numbers. The program must check that the user has not entered the value 0 for either of the two numbers. The program must also check that the user has entered one of the 4 value operations (add, subtract, multiply or divide). The program must perform the appropriate calculation and must display the results. Your assignment is to develop the conceptual model for this calculator. You can develop your conceptual model using either pseudo code or a flowchart.