static private ulong fact(ulong a)
factorial = factorial * i;
static private ulong npr(ulong a, ulong b)
ulong abfact = fact(a-b);
static private double mean(double a, double b)
static private double DectoPer(double a)
static private double PertoDec(double a)
public static void Main()
{ string restart= "This variablle will let you quit the program.";
Console.WriteLine("Please choose which option you would like to calculate");
Console.WriteLine("Press 1 for factorial, 2 to convert from decimal to percent, 3 to convert from percent to decimal, 4 for arrange and 5 for find mean.");
string choice = Console.ReadLine();
{ Console.WriteLine("Please enter the factorial");
ulong n = ulong.Parse(Console.ReadLine());
Console.WriteLine( "The factorial is: " + fact(n));
{Console.WriteLine("Please enter the decimal that you would like to convert.");
double n = double.Parse(Console.ReadLine());
Console.WriteLine( "The decimal converted to percent is: " + DectoPer(n));
{Console.WriteLine("Please enter the percent that you would like to convert.");
double n = double.Parse(Console.ReadLine());
Console.WriteLine( "The percent converted to decimal is: " + PertoDec(n));
{ Console.WriteLine("Please enter your total # of items.");
ulong n = ulong.Parse(Console.ReadLine());
Console.WriteLine("Please enter the number you would like to arrange.");
ulong r = ulong.Parse(Console.ReadLine());
Console.WriteLine( "The numbers of your arrange is: " + npr(n,r));
{ Console.WriteLine("Please enter your one number");
double n = double.Parse(Console.ReadLine());
Console.WriteLine("Please enter your other the number.");
double r = double.Parse(Console.ReadLine());
Console.WriteLine( "The mean of your numbers is: " + mean(n,r));
Console.WriteLine("Press q to quit the progress or any other key to continue.");
restart = Console.ReadLine();