Alinhamento de botões em uma janela

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;



public class Janela extends JFrame{
    private JLabel total, n1 ,n2, resultado;
    private JButton zero, um, dois, tres, quatro, cinco, seis, sete, oito, nove;
    private JButton somar, dividir, subtrair, multiplicar;
    private JTextField x, y;


    public Janela(){

        super("Calculadora");

        JPanel painel = new JPanel();
        
        this.setDefaultCloseOperation(EXIT_ON_CLOSE);
        this.setBounds(100,150,420,500);

        painel.setLayout(new GridLayout(5,5,5,5));
        this.getContentPane().add(painel);

        JPanel painelN1 = new JPanel(new FlowLayout(FlowLayout.LEFT));
        painel.add(painelN1);

        n1 = new JLabel("Insira o 1° Numero");
        painelN1.add(n1);

        JPanel painelX = new JPanel();
        painel.add(painelX);

        x = new JTextField(8);
        painelX.add(x);

        JPanel painelN2 = new JPanel(new FlowLayout(FlowLayout.LEFT));
        painel.add(painelN2);

        n2 = new JLabel("Insira o 2° Numero");
        painelN2.add(n2);

        JPanel painelY = new JPanel();
        painel.add(painelY);

        y = new JTextField(8);
        painelY.add(y);
        

        JPanel painelSoma = new JPanel(new FlowLayout(FlowLayout.LEFT));
        painel.add(painelSoma);

        somar = new JButton("+");
        painelSoma.add(somar);


        JPanel painelSubtrai = new JPanel(new FlowLayout(FlowLayout.LEFT));
        painel.add(painelSubtrai);

        subtrair = new JButton("-");
        painelSubtrai.add(subtrair);

        JPanel painelMultiplica = new JPanel(new FlowLayout(FlowLayout.LEFT));
        painel.add(painelMultiplica);

        multiplicar = new JButton("*");
        painelMultiplica.add(multiplicar);


        JPanel painelDivide = new JPanel(new FlowLayout(FlowLayout.LEFT));
        painel.add(painelDivide);

        dividir = new JButton("/");
        painelDivide.add(dividir);


        JPanel painel0 = new JPanel(new FlowLayout(FlowLayout.LEFT));
        painel.add(painel0);

        zero = new JButton("0");
        painel0.add(zero);


        JPanel painel1 = new JPanel(new FlowLayout(FlowLayout.LEFT));
        painel.add(painel1);

        um = new JButton("1");
        painel1.add(um);


        JPanel painel2 = new JPanel(new FlowLayout(FlowLayout.LEFT));
        painel.add(painel2);

        dois = new JButton("2");
        painel2.add(dois);


        JPanel painel3 = new JPanel(new FlowLayout(FlowLayout.LEFT));
        painel.add(painel3);

        tres = new JButton("3");
        painel3.add(tres);


        JPanel painel4 = new JPanel(new FlowLayout(FlowLayout.LEFT));
        painel.add(painel4);

        quatro = new JButton("4");
        painel4.add(quatro);


        JPanel painel5 = new JPanel(new FlowLayout(FlowLayout.LEFT));
        painel.add(painel5);

        cinco = new JButton("5");
        painel5.add(cinco);


        JPanel painel6 = new JPanel(new FlowLayout(FlowLayout.LEFT));
        painel.add(painel6);

        seis = new JButton("6");
        painel6.add(seis);


        JPanel painel7 = new JPanel(new FlowLayout(FlowLayout.LEFT));
        painel.add(painel7);

        sete = new JButton("7");
        painel7.add(sete);


        JPanel painel8 = new JPanel(new FlowLayout(FlowLayout.LEFT));
        painel.add(painel8);

        oito = new JButton("8");
        painel8.add(oito);


        JPanel painel9 = new JPanel(new FlowLayout(FlowLayout.LEFT));
        painel.add(painel9);

        nove = new JButton("9");
        painel9.add(nove);

        JPanel painelTot = new JPanel(new FlowLayout(FlowLayout.LEFT));
        painel.add(painelTot);

        total = new JLabel("TOTAL");
        painelTot.add(total);

        JPanel painelResult = new JPanel(new FlowLayout(FlowLayout.LEFT));
        painel.add(painelResult);

        resultado = new JLabel("");
        painelTot.add(resultado);


    }
        private class Acoes implements ActionListener{

            public void actionPerformed(ActionEvent e) {

            }


        }

}