In PowerPoint, you
can use the option "Header and Footer" to add the repeated information
(for example reference note, data, time, slide number) in the main
slides. This tip is very useful, when you want to add slide reference
note on every slide in your presentation.
Perform the given procedure to add header/footer in PowerPoint
presentation:
From View menu select "Header and Footer" option, a small dialog box
will appear with the title "Header and Footer".

Select "Slide" tab, now you can select "Fixed", "Date and time" option
or select "Update automatically Date and time under "Include on slide"
section.
To
add the number, check the "Slide number" option, and to add footer,
select "Footer "checkbox and type text that you want to appear as slide
footer.

Click on Apply button to save "Slide" tab settings.
Under "Notes and Handouts" tab, you can select also "Header" with all "Date and time" and
"Footer" options.

Once you have selected the all required options, click on "Apply to All"
button to save all settings.