While you are giving a presentation, you can draw on any slide (for example, to highlight a point).  To do so:

  1. Right-click anywhere on the slide
  2. Select PEN from the popup menu
  3. Draw on the slide
  4. Hit the right-arrow key to move on to the next slide

These last-minute drawings do not effect the slides themselves.  They are not saved.

Drawing

 

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