% This is used to add page numbers to a pdf file that does not already have them
% Put the name of the original PDF where it says "i-need-numbers.pdf"
% Then, run pdflatex and you will get a file "pdf-add-page-numbers.pdf"
% that is the original file, with page numbers added at the bottom center
% of each page

\documentclass[letterpaper,12pt]{article}
\usepackage{pdfpages}
\usepackage{amsfonts}

\setlength\topmargin{-0.375in}
\setlength\headheight{0in}
\setlength\headsep{0in}
\setlength\textheight{9.5in}
\setlength\textwidth{7.0in}
\setlength\oddsidemargin{-0.25in}
\setlength\evensidemargin{-0.25in}

\begin{document}

\includepdf[pages=-,pagecommand={\thispagestyle{plain}}]{i-need-numbers.pdf}

\end{document}