static void Main(string[] args)
{
mathematics obj = new mathematics();
Console.WriteLine("From AN, Hello World!");
Console.WriteLine("The output for addition is: " + obj.addition(1, 2));
System.Console.WriteLine("The output for subtraction is: " + obj.subtraction(1, 2));
Console.ReadLine();
}
public static int subtraction(this mathematics myobj, int firstnumber, int secondnumber)
{
return(firstnumber - secondnumber);
}