public double Substraction(double x, double y)
 {
     CalculatorApplication.Calculator calculator = new CalculatorApplication.Calculator();
     return x - y;
 }
 public double Division(double x, double y)
 {
     CalculatorApplication.Calculator calculator = new CalculatorApplication.Calculator();
     return x / y;
 }
 public double Multiplication(double x, double y)
 {
     CalculatorApplication.Calculator calculator = new CalculatorApplication.Calculator();
     return x * y;
 }
 public double Addition(double x, double y)
 {
     CalculatorApplication.Calculator calculator = new CalculatorApplication.Calculator();
     return x + y;
 }