OldCalculator.java

package calculator;

public class Calculator {
//    public static String num1 = null;
    public static String num2 = null;
    public static double v1 = 0;
    public static double value2 = 0;
    public static double ChooseCalculateMethod = 0;

    public static void main(String[] args) {

        System.out.println("Please, enter the first number ");
        MyScanner num1 = new MyScanner();
        String firstValue = num1.scanString();
        v1 = Double.parseDouble(firstValue);
        System.out.println("num1 =   " + v1);


        MyScanner scannerSign = new MyScanner();
        System.out.println("Please, enter the type of operation  ");
        while (true) {
            String mySign = scannerSign.scanString();

            if (mySign.equals("*")) {
                CalculateMethods multiplicateMe = new CalculateMethods();
                multiplicateMe.multiplication();
                ChooseCalculateMethod = 1;
                break;

            } else if (mySign.equals("/")) {
                CalculateMethods divideMe = new CalculateMethods();
                divideMe.division();
                ChooseCalculateMethod = 2;
                break;

            } else if (mySign.equals("+")) {
                CalculateMethods addMe = new CalculateMethods();
                addMe.addition();
                ChooseCalculateMethod = 3;
                break;

            } else if (mySign.equals("-")) {
                CalculateMethods subtractMe = new CalculateMethods();
                subtractMe.subtraction();
                ChooseCalculateMethod = 4;
                break;

            } else {
                System.out.println("try again..");
            }
        }


            MyScanner scanner2 = new MyScanner();
            System.out.println("Please, enter the second number ");
            num2 = scanner2.scanString();
            value2 = Double.parseDouble(num2);
            System.out.println("num2 =   " + value2);
            System.out.println("---------------------------------------");

            CalculateResult stepResult = new CalculateResult();
            double cycleResult = stepResult.calcResult(ChooseCalculateMethod);
            System.out.println("result = " + cycleResult);
        }
    }

package calculator;

public class CalculateMethods {

public void multiplication() {
    System.out.println("multiplication");
}

public void division() {
    System.out.println("division");
}

public void addition() {
    System.out.println("addition");
}

public void subtraction() {
    System.out.println("subtraction");
}

}

package calculator;

public class CalculateResult extends Calculator {

public double calcResult(double ChooseCalculateMethod) {

   double a = ChooseCalculateMethod;
    if(a == 1){
        a = Calculator.v1*Calculator.value2;

    }else if (a == 2){
        a = Calculator.v1/Calculator.value2;

    }else if (a == 3){
        a = Calculator.v1+Calculator.value2;

    }else if (a == 4){
        a = Calculator.v1-Calculator.value2;
    }

    return a;

}

}