Task

Task6.java

import javax.swing.*;
import java.awt.FlowLayout;
import java.awt.BorderLayout;
import java.awt.GridLayout;
import java.awt.event.*;

class Task6 extends JFrame implements ActionListener {
    final JTextField firstNumerator;
    final JTextField secondNumerator;
    final JTextField firstDenominator;
    final JTextField secondDenominator;
    final JLabel equalsLabel;

    public Task6() {
        setTitle("Fraction Calculator");
        setSize(380, 200);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setLayout(new BorderLayout());

        final JButton calcButton = new JButton("Calculate");
        calcButton.addActionListener((this));
        getContentPane().add(calcButton, BorderLayout.PAGE_END);

        final JPanel calcPanel = new JPanel(new FlowLayout());
        getContentPane().add(calcPanel, BorderLayout.CENTER);

        final JPanel firstFractionPanel = new JPanel(new GridLayout(2, 1));
        calcPanel.add(firstFractionPanel);

        firstNumerator = new JTextField("1", 1);
        firstNumerator.setFont(firstNumerator.getFont().deriveFont(30f));
        firstFractionPanel.add(firstNumerator);

        firstDenominator = new JTextField("8", 1);
        firstDenominator.setFont(firstDenominator.getFont().deriveFont(30f));
        firstFractionPanel.add(firstDenominator);

        final JLabel plusLabel = new JLabel("+");
        plusLabel.setFont(plusLabel.getFont().deriveFont(20.0f));
        calcPanel.add(plusLabel);

        final JPanel secondFractionPanel = new JPanel(new GridLayout(2, 1));
        calcPanel.add(secondFractionPanel);

        secondNumerator = new JTextField("5", 1);
        secondNumerator.setFont(secondNumerator.getFont().deriveFont(30f));
        secondFractionPanel.add(secondNumerator);
        
        secondDenominator = new JTextField("3", 1);
        secondDenominator.setFont(secondDenominator.getFont().deriveFont(30f));
        secondFractionPanel.add(secondDenominator);

        equalsLabel = new JLabel("= ?");
        equalsLabel.setFont(equalsLabel.getFont().deriveFont(50.0f));
        calcPanel.add(equalsLabel);
    }

    public void actionPerformed(ActionEvent e) {
        JButton button = (JButton)e.getSource();

        double a = Double.parseDouble(firstNumerator.getText());
        double b = Double.parseDouble(secondNumerator.getText());
        double c = Double.parseDouble(firstDenominator.getText());
        double d = Double.parseDouble(secondDenominator.getText());

        double sum = (a / c) + (b / d);
        equalsLabel.setText("= " + sum);
    }
    public static void main(String[] args) {
        Task6 app = new Task6();
        app.setVisible(true);
    }
}