How to calculate result of subjects in C#

How to calculate result of subjects in C#.png

Object 

Write a program that reads out marks sheet of a student. Take the marks of five subjects as input from the user and calculate the total marks, percentage and grade. Display the entire information on the console based on the following grade criteria. 

Total Marks	Grade
Greater than or equal to 90 but less than 100	A
Less than 90 but greater than or equal to 80	B
Less than 80 but greater than or equal to 70	C
Less than 70 but greater than or equal to 60	D
Less than 60	F

Code

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

namespace MarkSheet

{

    class Program

    {

        static void Main(string[] args)

        {

            int urdu, math, islamiate, computer, english;

            Console.WriteLine("\t\t!*$*$*$*$*$*$*$*$*$*$*$*$*$*$*$*$!");

            Console.WriteLine("\t\t!*********MARK SHEET*************!");

            Console.WriteLine("\t\t!*$*$*$*$*$*$*$*$*$*$*$*$*$*$*$*$!\n");

            Console.WriteLine("\t\tENTER THE MARKS\n");

            Console.WriteLine("English");

            english=int.Parse(Console.ReadLine());

            Console.WriteLine("Urdu");

            urdu = int.Parse(Console.ReadLine());

            Console.WriteLine("Math");

            math = int.Parse(Console.ReadLine());

            Console.WriteLine("Islamiate");

            islamiate = int.Parse(Console.ReadLine());

            Console.WriteLine("Computer");

            computer = int.Parse(Console.ReadLine());

           int totalMarks=math+urdu+islamiate+english+computer;

            Console.WriteLine("Total Marks : " +totalMarks);

           double per= (totalMarks * 100 / 500);

            Console.WriteLine("Percentage %  :" +per);

            if(per>=90 &&per<=100)

            {

            Console.WriteLine("Grade is     : \"A\"");

            }

            else if (per >= 80 && per < 90)

            {

                Console.WriteLine("Grade is     : \"B\"");

            }

           else if (per >= 70 && per <80)

            {

                Console.WriteLine("Grade is     : \"C\"");

            }

            else if (per >= 60 && per < 70)

            {

                Console.WriteLine("Grade is     : \"D\"");

            }

            else

            {

                Console.WriteLine("Grade is     : \"F\"");

            }

}

Screen Shot