Odd Output in Java (noobie error most likely)

Question

This will be my second question on here; I try not to ask because I don't fancy receiving help for my homework. But I'm just plain stuck.

I'm currently writing a program that stores and updates information for some example bank accounts. My issue is that, somehow, my output has two decimal points.

Example: "2000.02008.3333333333333"

Side notes: I'm in a Tier II java course, so yes, my code isn't the prettiest. Also, please only offer hints as to where I should make changes. As I said earlier, I try really hard not to ask for help and I don't want my request for help to be misconstrued as cheating. Finally, I do know about syso formatting and will be doing that with the Title information in my driver. The way I did it in there was just faster for me at the time while I fleshed out the rest of the details.

Many thanks in advance to any help provided!

Here's my current code:

public class SavingsAccount
{
  private static double annualInterestRate;
  private final int ACCOUNT_NUMBER;
  private double balance;

  public SavingsAccount(int ACCOUNT_NUMBER, double balance)
  {
    this.ACCOUNT_NUMBER = ACCOUNT_NUMBER;
    this.balance = balance;
  }

  public static double setAnnualInterestRate(double aIR)
  {
    annualInterestRate = aIR;
    return annualInterestRate;
  }

  public int getAccountNumber()
  {
    return ACCOUNT_NUMBER;
  }

  public double getBalance()
  {
    return balance;
  }

  public double addMonthlyInterest()
  {
    balance += (balance * annualInterestRate / 12);
    return balance;
  }
}

DRIVER

public class Chapter13
{
  public static void main(String[] args)
  {
    double annualInterestRate = .05;

    SavingsAccount saver1 = new SavingsAccount(10002, 2000);
    SavingsAccount saver2 = new SavingsAccount(10003, 3000);
    SavingsAccount.setAnnualInterestRate(annualInterestRate);
    System.out.println("Month    Acount#    Balance     Account#     Balance");

    for(int i = 0; i < 13; i++)
    {
      System.out.println(i + "    " + saver1.getBalance() + 
          saver1.addMonthlyInterest());
    }
  }
}

Answer 1

That's because the balance and annualInterestRate are getting printed without any space between them. Add a tab or space between them so that they are printed separately.

System.out.println(i + "    " + saver1.getBalance() + "\t" // tab
          saver1.addMonthlyInterest());
System.out.println(i + "    " + saver1.getBalance() + " " // space
          saver1.addMonthlyInterest());