     
     @IBOutlet weak var tipPercentSlider: UISlider!
     
-    // MARK: Init
     override func viewDidLoad() {
         super.viewDidLoad()
         

    }
    
    // MARK: Keyboard
    func addDoneButtonToKeyboard() {
        let numberToolbar = UIToolbar(frame: CGRectMake(0, 0, self.view.frame.size.width, 50))
        numberToolbar.barStyle = UIBarStyle.Default


    
    // MARK: Helpers
    
    func updateTipPersentLabel() {
        let percentValue = Int(tipPercentSlider.value)
        tipPercentLabel.text = "Tip (\(percentValue)%)"
