fields for headers/footers in Office

If Pearson requests that you include file name or type, page number, date, etc etc in your header/footer, they are asking you to use fields.

In Excel, on the Ribbon go to Page Layout tab > Page Setup > Header/Footer. Then select "Custom Header" or "Custom Footer" as appropriate. You'll see buttons for the various available fields. Simply click to insert.

In Word, double-click on the page in either the Header or Footer section as appropriate. Then, from the Ribbon, select the new tab for Header/Footer. You'll see the field buttons available on the Ribbon.

In PowerPoint, this is not relevant. You will instead have speaker's notes etc.