Grade Calculator Program in C#(Sharp)

                    Grade Calculator Program in C#(Sharp)

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

namespace cgpga
{
    class Program
    {
        static void Main(string[] args)
        {
            // creating the program for calculate the CGPA from percentage

            double first, second, third, fourth, fifth,CGPA;
            char option;
            Console.Write("Enter the Number of first subject ");
            first = Convert.ToDouble(Console.ReadLine());
            Console.Write("Enter the Number of second subject ");
            second = Convert.ToDouble(Console.ReadLine());
            Console.Write("Enter the Number of third subject ");
            third = Convert.ToDouble(Console.ReadLine());
            Console.Write("Enter the Number of fourth subject ");
            fourth = Convert.ToDouble(Console.ReadLine());
            Console.Write("Enter the Number of fifth subject ");
            fifth = Convert.ToDouble(Console.ReadLine());
            CGPA = ((first + second + third + fourth + fifth) / 5) / 9.5; // we are divide percentage to 9.5 for calculating the CGPA
            Console.WriteLine("Your CGPA is=>"+CGPA);


            if (CGPA >= 8) // checking the condition for the Grad.
            {
    
                option = '1';
           }

            else if (CGPA >= 6.5 && CGPA <8)
           {

                option = '2';

           }

            else if (CGPA >= 3.5 && CGPA < 6.5)

            {

                option = '3';

            }

            else

            {

                option = 'F';

            }
                switch (option)  //checking the condition for the Grad

            {

                case '1': Console.WriteLine("Grade: First Class with Distinction"); break;
                case '2':Console.WriteLine("Grade: second Class");break;
                case '3':Console.WriteLine("Grade: Third Class Class");break;
                case 'F':Console.WriteLine("Grade: Fail");break;
                default:Console.WriteLine("Invalid GRADE");break;

             }       
                Console.ReadLine();
    }
  }
}

Output==>