private void updateBalance(TextField operation, BigDecimal value) throws IOException{
        if(operation.equals(addField)){
        balance = balance.add(value);    
        }
        else if(operation.equals(subtractField)){
        balance = balance.subtract(value);
        }
        
        balance = balance.setScale(2, RoundingMode.FLOOR);
        logWriter.writeToFile("The new balance is:");
        logWriter.writeToFile(balance.toString());
        balanceField.setText("$" + balance.toString());
    }