Conditional statements - 10. ApplyBonuses

using System;
using System.Linq;
using System.Text;

namespace _10.ApplyBonusScore
{
    class ApplyBonusScore
    {
        static void Main(string[] args)
        {
            bool isInteger;
            byte number;

            Console.WriteLine("Enter number in interval [1-9]");
            isInteger = byte.TryParse(Console.ReadLine(), out number);

            if (isInteger && number > 0 && number < 10)
            {
                Console.WriteLine("Result: " + MultiplyNumber(number));
                return;
            }

            Console.WriteLine("Error");
        }

        private static int MultiplyNumber(byte number)
        {
            //if (number <= 3)
            //{
            //    return number * 10;
            //}

            //if (number <= 6)
            //{
            //    return number * 100;
            //}

            //if (number <= 9)
            //{
            //    return number * 1000;
            //}

            //This line does the same as the commented code in the method.
            return (int) (number * Math.Pow(10,((number -1) / 3) + 1));

            //return number;
        }
    }
}