You can add page numbers to your PowerPoint slideshow through the "Slide Master" page, which lets you edit your entire slideshow at once.

Then, to add a zoom animation effect to your slide, duplicate the slide. For this, select the slide in the left pane, right-click it and choose ‘ Duplicate Slide ’ option.

You can add Slide Numbers and Date and Time to your PowerPoint presentation to make it more impressive, and this post shows how to do that.