SimpleCalculator

public class SimpleCalculator {
    private double firstNumber;
    private double secondNumber;

    public double getFirstNumber(){
        return firstNumber;
    }

    public double getSecondNumber(){
        return secondNumber;
    }

    //Remember that using the "this" keyword is meaning the field, so this.FIELD
    //is having the parameter's value that was passed to this method updating the field value
    public void setFirstNumber(double firstNumber){
        this.firstNumber = firstNumber;
    }

    public void setSecondNumber(double secondNumber){
        this.secondNumber = secondNumber;
    }

    //Remember to declare the data type of the method and any objects being initialized
    public double getAdditionResult(){
        double sum = firstNumber + secondNumber;
        return sum;
    }

    public double getSubtractionResult(){
        double diff = firstNumber - secondNumber;
        return diff;
    }

    public double getMultiplicationResult(){
        double mult = firstNumber * secondNumber;
        return mult;
    }

    public double getDivisionResult(){
        double div = firstNumber / secondNumber;
        if(secondNumber == 0){
            return 0;
        } return div;
    }
}