To add a slide that contains the content of an existing slide in a presentation, you can duplicate the slide.
Important: If you need paste recovery, which allows you to keep the formatting of the duplicated slide's content, you will want to copy and paste the slides.
In the pane that contains the Outline and Slides tabs, click the Slides tab.
Select one or more slides that you want to duplicate.
On the Home tab, in the Slides group, click New Slide.
In the layout gallery, click Duplicate Selected Slides.
Note: The duplicated slides are inserted directly below the lowermost slide that you selected.