- Slide numbers should be added.
- Click Normal in the Presentation Views group on the View tab.
- Click the first slide thumbnail in your presentation in the pane on the left of your screen that includes the slide thumbnails.
- Click Header & Footer in the Text group on the Insert tab.
- Do one of the following in the Header and Footer dialogue box: If you want to number your slides, go to the Slide tab and check the Slide number check box.
- Click Apply to All if you want page numbers on all of your presentation's slides or notes pages.
- Click Slide Size > Custom Slide Size in the Customize group on the Design menu.
- Select a beginning number from the Number Slides from drop-down list in the Slide Size box.
Read More: What is a slide shorter view?