Ignoring page numbers in backup slides

Question

I am using the beamer document class in latex to make a presentation. I will have a number of back up slides which are there for offline viewing, reference etc. Beamer has a f

Answer 1

Just insert

\renewcommand{\inserttotalframenumber}{\pageref{lastslide}}

after \begin{document}, and place the marker

\label{lastslide}

on your last slide.