This article explains how to combine two or more PowerPoint presentations into one presentation. Whether you use Mac or PC versions of PowerPoint, it's easy to combine PowerPoint presentations.
How to Merge PowerPoint Presentations ⏩ | PowerPoint
Microsoft PowerPoint offers the option to reuse slides. This method does not require you to open all of your PowerPoint presentations, so it is the fastest and easiest way to combine presentations.
Open your main PowerPoint presentation. You can choose the largest presentation, or any presentation that you want to keep the formatting of.
Go to the Home tab in the top left corner.