Adding a summary slide to the end of a PowerPoint presentation is a good idea. That way, you can review items with your audience. To create a summary slide, select all of the slides you want to summarize (from the Slides tab in Normal View) and then click Summary Slide on the Outlining toolbar. PowerPoint inserts the summary slide before the slides, so be sure to drag it to the end of the presentation.
If that’s the end of things, the summary slide, as is, is adequate. However, you might find the summary items prompt questions from the audience. If that’s a possibility, and you’re willing to continue the presentation to answer questions, hyperlink the summary items to their respective slides as follows:

  1. Select the item on the summary slide.
  2. Choose Hyperlink from the Insert menu.
  3. Click Place In This Document.
  4. Identify the slide.
  5. Click OK.

With the summary slide on screen, you can click any of the hyperlinked items to return to the original slide for a quick review. Just be sure to add hyperlinks on each slide for the return trip to the summary slide.