title: Cannot invoke initializer for type 'Int' with an argument list of type '(Number)'
body: <p><strong>This program can't compile by Xcode, it only run in IOS application "Playgrounds".</strong></p>
  
  <p>In IOS application "Playgrounds" -> "Learn to Code 3"(Swift 3.1) ->"Music Universe" I have below code:</p>
  
  <pre><code>// A touch event for when your finger is moving across the scene.
  
  // Declaration
  struct Touch
  
  // The position of this touch on the scene.
  
  // Declaration
  var position: Point
  
  // The x coordinate for the point.
  
  // Declaration for touch.position.x
  var x: Double
  </code></pre>
  
  <p>The above just for explanation.</p>
  
  <pre><code>let touch: Touch
  let numberOfNotes = 16
  let normalizedXPosition = (touch.position.x + 500) / 1000
  let note = normalizedXPosition * (numberOfNotes - 1)
  let index = Int(note)
  </code></pre>
  
  <p>The last sentence show error:
  Cannot invoke initializer for type 'Int' with an argument list of type '(Number)'.
  How can I convert <code>note</code> to <code>Int</code> type?</p>