simple calculator for add, sub, multi, div, square and sqrt in java

import java.util.*; //importing utility class for user input
//class that contains all methods
class SimpleCalculator{
 int num1,num2,result,remainder;
 double result2;
 Scanner input=new Scanner(System.in); //for user input
 void add(){
  System.out.print("Enter number for addition : ");
  num1=input.nextInt();
  num2=input.nextInt();
 result = num1+num2;
 System.out.println("Sum of numbers is :" +result);
 }
 void sub(){
  System.out.print("Enter number for subtraction : ");
  num1=input.nextInt();
  num2=input.nextInt();
 result = num1-num2;
 System.out.println("Diff. of numbers is :" +result);
 }
 void div(){
  System.out.print("Enter number for division : ");
  num1=input.nextInt();
  num2=input.nextInt();
 result2 = num1/num2;
 remainder = num1%num2;
 System.out.println("Division of numbers is :" +result2  + remainder);
 }
 void multi(){
  System.out.print("Enter number for multiplication : ");
  num1=input.nextInt();
  num2=input.nextInt();
 result = num1*num2;
 System.out.println("multiplication of numbers is :" +result);
 }
 void sqr(){//square of any number
  System.out.print("Enter number for square : ");
  num1=input.nextInt();
 result = num1+num1;
 System.out.println("Sqr of numbers is :" +result);
 }
 void sqrt(){//for square root of number
  System.out.print("Enter number for squre root : ");
  num1=input.nextInt();
 result2 = Math.sqrt(num1);
 System.out.println("sqrt of numbers is :" +result2);
 }
}
/*
  Calculator is the main class, save program as Calculator.java than compile and run it
*/
class Calculator{
public static void main(String[] arr){
  SimpleCalculator obj = new SimpleCalculator();
 Scanner input = new Scanner(System.in);
System.out.println("Enter 1 for addition and 2 for subtracion");
System.out.println("Enter 3 for division and 4 for multiplication ");
System.out.println("Enter 5 for square and 6 for square root ");
int n = input.nextInt();
/*Switch is used for user choice what user want addition subtraction division etc. */
switch(n){
    case 1 :
obj.add();
break;
case 2 :
obj.sub();
break;
case 3 :
obj.div();
break;
case 4 :
obj.multi();
break;
case 5 :
obj.sqr();
break;
case 6 :
obj.sqrt();
break;
}
  }
}

/*
output :
Enter 1 for addition and 2 for subtracion
Enter 3 for division and 4 for multiplication
Enter 5 for square and 6 for square root
if user want to calculate multiplication enter 4
Enter number for multiplication :
4
8
multiplication of numbers is : 32
*/