06.FourDigitNumber

using System;

class FourDigitNumber
{
    static void Main()
    {
        Console.WriteLine("Please give us a four-digit number");
        Console.Write("your number : ");
        int number = int.Parse(Console.ReadLine());

        // fourth digit
        int firstDigit = number % 10;

        // third digit
        int restNumberTwo = number / 10;
        int secondDigit = restNumberTwo % 10;

        // second digit
        int restNumberThree = number / 100;
        int thirdDigit = restNumberThree % 10;

        // first digit
        int restNumberFour = number / 1000;
        int fourthDigit = restNumberFour % 10;

        Console.WriteLine("Your number is : " + number);
        Console.WriteLine("The sum of digits is : " + (firstDigit + secondDigit + thirdDigit + fourthDigit));
        Console.WriteLine("Digits were reversed {0}{1}{2}{3}" ,firstDigit ,secondDigit ,thirdDigit ,fourthDigit);
        Console.WriteLine("Last digit go at front {0}{1}{2}{3}" ,firstDigit ,fourthDigit ,thirdDigit ,secondDigit);
        Console.WriteLine("Second and third digits exchanged {0}{1}{2}{3}" ,fourthDigit ,secondDigit ,thirdDigit ,firstDigit);
        Console.WriteLine("Enjoy yourself - see you !");
    }
}