FizzBuzz division

gistfile1.cs

// FizzBuzz without modulo
public class Program
{
    public static void Main()
    {
        for (int i = 1; i <= 100; i++)
        {
            Console.WriteLine(FizzBuzz(i));
        }

        Console.ReadKey();
    }
    public static bool IsFizz(int number)
    {
        double value = number / 3.0;
        return CheckForZeroDecimal(value);
    }

    public static bool IsBuzz(int number)
    {
        double value = number / 5.0;
        return CheckForZeroDecimal(value);
    }

    public static bool CheckForZeroDecimal(double value)
    {
        var formattedNumber = string.Format("{0:N1}", value);
        int dotIndex = formattedNumber.IndexOf(",", StringComparison.Ordinal);
        return formattedNumber.Substring(dotIndex + 1, 1) == "0";
    }

    public static string FizzBuzz(int number)
    {
        string s = null;
        if (IsFizz(number))
            s += "fizz";
        if (IsBuzz(number))
            s += "buzz";
        return s ?? number.ToString();
    }
}