         buttons.append(CPButton(int: 7))
         buttons.append(CPButton(int: 8))
         buttons.append(CPButton(int: 9))
-        buttons.append(CPButton(text: "/"))
+        buttons.append(CPButton(text: "÷"))
         buttons.append(CPButton(text: "AC"))
         buttons.append(CPButton(int: 4))
         buttons.append(CPButton(int: 5))
         buttons.append(CPButton(int: 6))
-        buttons.append(CPButton(text: "x"))
-        buttons.append(CPButton(text: "+/-"))
+        buttons.append(CPButton(text: "×"))
+        buttons.append(CPButton(text: "⁺∕₋"))
         buttons.append(CPButton(int: 1))
         buttons.append(CPButton(int: 2))
         buttons.append(CPButton(int: 3))

    
    func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
        let cell = collectionView.dequeueReusableCellWithReuseIdentifier("CPButtonCollectionViewCell", forIndexPath: indexPath) as! CPButtonCollectionViewCell
        cell.data = buttonFrom(indexPath)
        cell.button.setTitle(cell.data.text, forState: .Normal)
        cell.button.addTarget(self, action: #selector(buttonPressed(_:)), forControlEvents: .TouchUpInside)
        
        return cell
    }
    
    func buttonPressed(sender: AnyObject) {
        let button = sender as! UIButton
        let cpButton = CPButton(text: button.currentTitle!)
        if shouldAppendToResultLabel(cpButton) {
            appendText(cpButton.text)
        }
    }
    

    let numberOfSections = 4
    let numberOfColumns = 5
    let spacingZero = 0
    var previousNumber = 0.0
    var currentModifier: CPButton?
    
    required init?(coder aDecoder: NSCoder) {
        buttons = [CPButton]()
