Hi Joan of Art,
You can use a NUMWORDS field (Press Alt-i, f to open the Insert|Fields dialogue and select 'Numwords' from the list of fields.
Note that the NUMWORDS field doesn't count anything in textboxes, embedded objects (eg Excel worksheets), headers, footers,
footnotes or endnotes, and only counts hidden text if Word is configured to print hidden text. Depending on where you've inserted
them, footnote and endnote reference markers may or may not be counted.