C # "Math" Program modified according to suggestion

Question

I modified C# "Math" Program  according to suggestion but it is not working. Please correct it.
If one entered a number, squre root of that number should be the output. That means for example: If I entered 10 as a input, output should be 3.1622.
square root of 10 = 3.1622.
using System;
public class Math
{
public static void Main()
{
double sqrt, number;
string sNum;
Console.Write("Number = ");
sNum = Console.ReadLine();
number = Convert.ToDouble(sNum);
sqrt = SqrtRoot(number);
Console.WriteLine("Square Root of the number = {0}", sqrt);
}
public static double SqrtRoot( double num)
{
double sRoot;
sRoot = Math.Sqrt(num);
return sRoot;
}
}

Answer

Thank you for your help, Maha
not that Console . ReadLine (); but it is  System . Math . Sqrt ( num ); correcting the program.

Mike Gold · Answer

you need a ReadLine before the end of main so it doesn't exit before you see the output.  Here is the solution:
Best,
Mike G.
using System ;
public class Math
{
public static void Main ()
{
double sqrt , number ;
string sNum ;
Console . Write ( "Number = " );
sNum = Console . ReadLine ();
number = Convert . ToDouble ( sNum );
sqrt = SqrtRoot ( number );
Console . WriteLine ( "Square Root of the number = {0}" , sqrt );
Console . ReadLine ();
}
public static double SqrtRoot ( double num )
{
return System . Math . Sqrt ( num );
}
}