PBO - Tugas kelompok 2

Program sederhana
disini kelompok kami mencoba membuat kalkulator

dan inilah sourcecode nya :
/*
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package pbo;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

/**
 *
 * @author Dwi Rahayu Utami
 */
public class kalkulator {
    private static int tambah(int a, int b) {
        return (a + b);
    }

    private static double tambah(double a, double b) {
        return (a + b);
    }

    private static int kurang(int a, int b) {
        return (a - b);
    }

    private static double kurang(double a, double b) {
        return (a - b);
    }

    private static int bagi(int a, int b) {
        return (a / b);
    }

    private static double bagi(double a, double b) {
        return (a / b);
    }

    private static int kali(int a, int b) {
        return (a * b);
    }

    private static double kali(double a, double b) {
        return (a + b);
    }

    public static void Jalankan() throws IOException{
   
        BufferedReader input = new BufferedReader(new InputStreamReader(System.in));
        System.out.println("1. Bilangan Bulat");
        System.out.println("2. Bilangan desimal");
        System.out.print("====Pilih   :");
        int pilih = Integer.parseInt(input.readLine());
        if (pilih == 1) {

            System.out.println ("1. Bilangan Bulat");
            System.out.println("======================");
            System.out.print("Masukkan Angka pertama  = ");
            int a = Integer.parseInt(input.readLine());
            System.out.print("Masukkan angka kedua    = ");
            int b = Integer.parseInt(input.readLine());
            System.out.println("=========================");
            System.out.println("1. Tambahakan");
            System.out.println("2. Kurangkan");
            System.out.println("3. Kalikan");
            System.out.println("4. Bagikan");
            System.out.print("==Pilih angka  :  ");
            int c = Integer.parseInt(input.readLine());
            switch (c) {
                case 1:
                    System.out.println("Penambahan");
                    int tambah = tambah(a, b);
                    System.out.print(a + "+" + b + "= " + tambah);
                    break;
                case 2:
                    System.out.println("Pengurangan");
                    int kurang = kurang(a, b);
                    System.out.print(a + "-" + b + "= " + kurang);
                    break;
                case 3:
                    System.out.println("Perkalian");
                    double kali = kali(a, b);
                    System.out.print(a + "x" + b + "= " + kali);
                    break;
                case 4:
                    System.out.println("Pembagian");
                    double bagi = bagi(a, b);
                    System.out.print(a + ":" + b + "= " + bagi);
                    break;

            }
        }
        if (pilih == 2) {
            System.out.println("2. Bilangan desimal");
            System.out.print("Masukkan Angka pertama  =");
            double a = Double.parseDouble(input.readLine());
            System.out.print("Masukkan Angka kedua    =");
            double b = Double.parseDouble(input.readLine());
            System.out.println("=========================");
            System.out.println("1. Tambahakan");
            System.out.println("2. Kurangkan");
            System.out.println("3. Kalikan");
            System.out.println("4. Bagikan");
            System.out.print("==Pilih angka  :  ");
            int angka = Integer.parseInt(input.readLine());
            switch (angka) {
                case 1:
                    System.out.println("Penambahan");
                    double tambah = tambah(a, b);
                    System.out.print(a + "+" + b + "= " + tambah);
                    break;
                case 2:
                    System.out.println("Pengurangan");
                    double kurang = kurang(a, b);
                    System.out.print(a + "-" + b + "= " + kurang);
                    break;
                case 3:
                    System.out.println("Perkalian");
                    double kali = kali(a, b);
                    System.out.print(a + "x" + b + "= " + kali);
                    break;
                case 4:
                    System.out.println("Pembagian");
                    double bagi = bagi(a, b);
                    System.out.print(a + ":" + b + "= " + bagi);
                    break;
            }
        }
    }
     public static void main(String[] args) throws IOException {
      Jalankan();
    }
   
}

silahkan dilihat hasilnya :)