This theme uses the tcolorbox package to put each exercisee in a box.
With two columns.
\documentclass[10pt]{article}
\usepackage{webwork2}
\usepackage[text={7in,9in},centering]{geometry}
\usepackage{tcolorbox}
\tcbuselibrary{breakable, skins}
\newtcolorbox{webworkexercise}[2]{
breakable,
enhanced jigsaw,
title={
{\bfseries\webworkLocalizeProblem~\ifthenelse{\equal{#1}{}}{\#}{#1}}\hfill
(\ifthenelse{\equal{#2}{}}{\#}{#2}~\webworkLocalizePoint)
}
}
\setlength{\columnsep}{.2in}
\usepackage{fancyhdr}
\parindent=0pt
\setlength{\parskip}{1pc}
\pagestyle{fancy}
\begin{document}
\renewcommand{\headrulewidth}{0pt}
\fancyhead[L]{\webworkLeftHeader}
\fancyhead[C]{\webworkCenterHeader}
\fancyhead[R]{\webworkRightHeader}
\fancyfoot[L]{\webworkLeftFooter}
\fancyfoot[C]{\webworkCenterFooter}
\fancyfoot[R]{\webworkRightFooter}
\medskip
\begin{multicols*}{2}
%
\begin{webworkexercise}{\webworkProblemNumber}{\webworkProblemWeight}%
%
\end{webworkexercise}%
\smallskip
\goodbreak
\end{multicols*}
\newpage%
\setcounter{page}{1}%
\newpage%
\setcounter{page}{1}%
\end{document}