Calculate Sum of the digits of a given number

Module sumofdigits

    Sub Main()
        Dim n, sum, r As Integer
        Console.Write("Enter a Number: ")
        n = CInt(Console.ReadLine())
        sum = 0
        While n <> 0
            r = n Mod 10
            sum += r
            n \= 10
        End While
        Console.WriteLine("Sum of Digits=" + sum.ToString())
        Console.ReadLine()
    End Sub

End Module