Methods 2: the Tip Calculator

Here is the code with comments

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace TipCalculator
{
    class Program
    {
        /*
            Get the amount of the bill
            Get the tip percent
            Get the tax
            calculate the tax
            calculte the tip
            Get the total
            Display the amount, the tax and the total

    */
    //since every method uses this I set it at Class Scope
        double amount=0;
        static void Main(string[] args)
        {
            //initialize the class
            Program p = new Program();
            //call get amount
            p.GetAmount();
            //call calculate total which calls all the 
            //other methods
            p.CalculateTotal();
            p.PauseIt();
           

        }

        void GetAmount()
        {
            //this method gets the amount 
            Console.WriteLine("Enter the Amount");
            amount = double.Parse(Console.ReadLine());
        }

        double GetTipPercent()
        {
            //in this method we create a simple menu
            //to give the user a choice of tip options
            double tipPercent = 0;
            int choice = 0;
            Console.WriteLine("Choose your tip Percent");
            Console.WriteLine("1 for 10 Percent");
            Console.WriteLine("2 for 15 Percent");
            Console.WriteLine("3 for 20 Percent");
            Console.WriteLine("4 for other");
            choice = int.Parse(Console.ReadLine());
            //the switch analyses their choice and assigns
            //the appropriate tip
            switch (choice)
            {
                case 1:
                    tipPercent = .1;
                    break;
                case 2:
                    tipPercent = .15;
                    break;
                case 3:
                    tipPercent = .2;
                    break;
                case 4: 
                    //when choosing other we give them the 
                    //opportunity to enter their own tip amount
                    Console.WriteLine("Enter your alternate tip amount");
                    tipPercent = double.Parse(Console.ReadLine());
                    //make sure it is in decimal form
                    if (tipPercent > 1)
                    {
                        tipPercent =tipPercent/ 100;
                    }
            
                    break;
                default:
                    Console.WriteLine("Not a valid choice.");
                    break;
            }
            return tipPercent;

        }

        double GetTaxPercent()
        {
            //let the user enter the tax percent
            Console.WriteLine("Enter The tax Percent");
            double taxPercent = double.Parse(Console.ReadLine());
            if (taxPercent > 1)
            {
                taxPercent /= 100;
            }

            return taxPercent;
        }

        double CalculateTax()
        {
            //calculate the tax --calls
            //get Tax percent
              double tax=amount * GetTaxPercent();
               return tax;
        }

        double CalculateTip()
        {
            //calculate tip calls GetTipPercent
            return amount * GetTipPercent();
        }

        void CalculateTotal()
        {
            //CalculateTip calls GetTipPercent
            //CalculateTax call GetTaxPercent.
            //This method also calls Display,
            //so this is the only method besides
            //GetAmount that we need to call
            //From Main
            double tip = CalculateTip();
            double tax = CalculateTax();
            double total = amount + tax + tip;
            //call display and pass the values
            Display(tip, tax, total);

        }

        void Display(double tip, double tax, double total)
        {
            //display the results
            Console.WriteLine("Your amount is {0}", amount);
            Console.WriteLine("the tip is {0}", tip);
            Console.WriteLine("Your tax is {0}", tax);
            Console.WriteLine("the Total is {0}", total);
        }

        void PauseIt()
        {
            //pause the console
            Console.WriteLine("Press any key to exit");
            Console.ReadKey();
        }

    }
}

Here is the diagram we drew of how the methods execute