To edit a footer in your PowerPoint slides and include citations or notes, you'll need to access the Header & Footer menu ...
You can add page numbers to your PowerPoint slideshow through the "Slide Master" page, which lets you edit your entire slideshow at once.
To manually crop a picture in Microsoft Word, Excel, or PowerPoint, select it, and in the Picture Format tab on the ribbon, click the top half of the split "Crop" button.