You can add sequential numbers to your slides to help you order them during a presentation.
Adding Page Numbers
You can add sequential numbers to your slides to help you order them during a presentation. Add a page number to your master if you want the page number to appear on all slides based on that master.
Select a slide, and on the Edit tab click the Insert button. Select Page Number. A number in a text box will appear, which you can move anywhere on your slide. If you move a slide in the Presentation Outline, the slide numbers will automatically update.
Additional Slide Number Options
For more slide number options, right-click your desired slide in the Presentation Outline, and select Slide Properties. On the Slide Format tab, you can choose what slide number to start with, use different styles, add a prefix to your slide numbers, and a separator in between a prefix and the slide number.