Calculate Average and Percentage using C#

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace ConsoleApplication1
{
    class Program //Calculate the Average marks and percentage for students
    {
        static void Main(string[] args)
        {
            float average, percentage, total = 500f;
            float maths, science, english, physics, chemistry;
            String StudentName;
            Console.WriteLine("Enter the name for Student to Calculate the Average and Percentage");
            StudentName = Console.ReadLine();
            Console.WriteLine("Creating Report for the student :{0}", StudentName);
            System.Threading.Thread.Sleep(5000);
            Console.WriteLine("Enter Marks for Maths for range 0-100");
            maths = float.Parse(Console.ReadLine());
            Console.WriteLine("Enter Marks for Science for range 0-100");
            science = float.Parse(Console.ReadLine());
            Console.WriteLine("Enter Marks for English for range 0-100");
            english = float.Parse(Console.ReadLine());
            Console.WriteLine("Enter Marks for Physics for range 0-100");
            physics = float.Parse(Console.ReadLine());
            Console.WriteLine("Enter Marks for Chemistry for range 0-100");
            chemistry = float.Parse(Console.ReadLine());
            Console.WriteLine("Validating Marks....");
            System.Threading.Thread.Sleep(3000);
            average = (maths + science + english + physics + chemistry) / total;
            Console.WriteLine("Average score is :{0}", average);
            percentage = average * 100;
            Console.WriteLine("Percentage obtained by student is: {0}", percentage);
            Console.ReadLine();
        }
    }
}