Thread: How to store a number that was inputted by the user? please help

Hey people im just wondering is there a way to store a number without using the non-void methods
heres my code my code works grand but i need to store the balence and by how much it was topped up by if u get me drift

class Rough1{
   public static void main(String[] args)
   {
    showServiceMenu();
   }
 
   // Declare Global Variables
   int input=0;
 
   public static void showServiceMenu()
   {
   // Local Variables
    int input=0;
    String password = "me";
    int cardnum = 123;
    double balence=0;
    double add=0;
    double purchase;
    char option;
    char stop = 'x';
 
		// Loop to repeat the program until x is entered
    do{
    System.out.println("Login: Press 1");
    System.out.println("Customer Details: Press 2");
		System.out.println("Customer Balence: Press 3");
		System.out.println("Top-Up: Press 4");
		System.out.println("Purchase: Press 5");
		input = Keyboard.readInt();
 
   if(input==1){
   System.out.println("Please enter in your Debit Card number and password ");
   System.out.println("Debit Card Number: ");
   cardnum = Keyboard.readInt();
   System.out.println("Password: ");
	 password = Keyboard.readString();}
 
	 if(input==2){
	 System.out.println("Your Details ");
	 System.out.println("Name: Shane Lowry ");
	 System.out.println("Address: 9 Sheepmoor Ville ");
	 System.out.println("Card Number: 123");}
 
   if(input==3){
   System.out.println("Your balence is "+balence);}
 
   if(input==4){
   System.out.println("How much would you like to top-up");
   add = Keyboard.readDouble();
   if(add <= 100)
   System.out.println("Your new balence is "+(add+balence));
   else
   System.out.println("Your cannot add more than 100");}
 
   if(input==5){
   System.out.println("How much would you like to spend?");
   purchase = Keyboard.readDouble();
   if(purchase>balence){
   System.out.println("You don't have enough money to make a purchase");}
   else if(purchase<=balence){
   System.out.println("Thank you, you have made a purchase for "+purchase);}
   }
   System.out.println("Do you want to continue?");
	 option = Keyboard.readChar();
   if(option=='x'){
	 System.out.print("Goodbye");}
   }while(option!='x');
	}
}

yh im sorry im new and well im stupid so i kinda understand what you are saying but not fully if u get me but i trying to store the number when i top-up so when i go to purchase it will subtraction the purchase from the new balence which is in this case (add+balence) you get me?