PowerPoint 2016 - Do not enumerate hidden slides

As Steve Rindsberg said, you may use such a VBA macro as found here: vba-number-the-slide-if-they-are-visible

The necessary steps for me were

• saving the presentation in with-macros-format (as a file with dot-pptm ending)
• pressing Alt+F11 (or on mac hit Tools -> Macros -> Visual Basic Editor)
• entering the code from aforementioned StackOverflow answer
• pressing either F5 or the green run arrow