Java Calculator using instance variable

Design and Write  a simple java class program which can perform all basic operation of a Calculator. Define necessary instance variable but do not use method.

Reference:
1. http://c-programming-sourcecode.blogspot.com/2012/06/write-program-performing-as-calculator.html?q=simple+interest

2. Course Book(The Complete Reference Java j2se) ; Page 106

Source Code:

package calculator_shohan;
import java.util.Scanner;
import java.io.*;
public class Calculator_shohan {
public static void main(String[] args) {
calculator_ c=new calculator_();
int num1=0,num2=0;
Scanner input=new Scanner(System.in);
System.out.println("Enter the first number:");
num1=input.nextInt();
System.out.println("Enter the second number:");
num2=input.nextInt();
c.cal(num1, num2);
}

}
class calculator_
{
int add=0,sub=0,div=0,mul=0,mod=0;
public void cal(int x,int y)
{
Scanner input=new Scanner(System.in);

char ch;
System.out.println("Enter your choice:");
System.out.println("Addition for + :");
System.out.println("Subtraction for - :");
System.out.println("Multiplication for * :");
System.out.println("Divition for /:");
System.out.println("Modulation for %:");
ch=input.next().charAt(0);
switch(ch)
{
case '+':
System.out.println(x+y);
break;

case '-':
System.out.println(x-y);
break;

case '*':
System.out.println(x*y);
break;
case '/':
System.out.println(x/y);
break;
case '%':
System.out.println(x%y);
break;
default:
System.out.println("no choice");
}
}
}