static void Main(string[] args)
{
NormalCalculator n1 = new NormalCalculator();
n1.sum(10, 20);
n1.sub(40, 20);
n1.multiplication(15, 10);
n1.division(100, 20);
Console.WriteLine();
ScientificCalculator s1 = new ScientificCalculator();
s1.XtoY(5, 10);
s1.SquareRoot(8);
}