private void EqualButton_Click(object sender, RoutedEventArgs e) { double newNumber; if (double.TryParse(resultLabel.Content.ToString(), out newNumber)) { ; switch (selectedOperator) { case SelectedOperator.Addition: { result = SimpleMath.Add(lastNumber, newNumber); } break; case SelectedOperator.Subtraction: { result = SimpleMath.Subtract(lastNumber, newNumber); } break; case SelectedOperator.Multiplication: { result = SimpleMath.Multiply(lastNumber, newNumber); } break; case SelectedOperator.Division: { result = SimpleMath.Divide(lastNumber, newNumber); } break; default: break; } resultLabel.Content = result.ToString(); lastNumber = result; lastLabel.Content = ""; lastLabel.Content = lastNumber.ToString(); } }