using System;

public class Program

{

    public static void Main()

    {

        Calcula("+",1,2);

        Calcula("-",1,2);

        Calcula("*",1,2);

        Calcula("/",1,2);

    }

    public static void Calcula(string theOperator, double total1, double total3)

    {

        double total2 = 0;                          

        //Encapsulo os métodos

        Func<double,double,double> soma = (a,b) => a + b;

        Func<double,double,double> subtracao = (a,b) => a - b;

        Func<double,double,double> multiplicacao = (a,b) => a * b;

        Func<double,double,double> divisao = (a,b) => a / b;

        Func<double,double,double> operacao = null;

        if (theOperator == "+") {

           operacao = soma;

        }

        else if (theOperator == "-") {

           operacao = subtracao;

        }

        else if (theOperator == "*") {

           operacao = multiplicacao;

        }

        else if (theOperator == "/") {

           operacao = divisao;

        }

        else {

          // MessageBox.Show("Este simbolo não é reconhecido", "Erro", MessageBoxButtons.OK, MessageBoxIcon.Error);

        }

        total2 = operacao(total1,double.Parse(total3.ToString()));  

        Console.WriteLine(total2);

    }   

}