For the sake of variety, here's a LuaLaTeX-based solution. It sets up a user macro called \myPerCent which takes 2 mandatory arguments -- the numerator and denominator terms of the ratio to be computed -- as well as 1 optional argument -- the desired precision or number of significant digits.
Two remarks about this solution:
The macro's default number of significant digits is
3. This can be overridden by specifying an optional argument, enclosed in square brackets, ahead of the 2 mandatory arguments. See the sample code below for details.The 2 mandatory arguments of
\myPerCentdon't have to be numbers. They can also be expressions that to evaluate to numbers using standard math and LaTeX syntax rules.
% !TEX TS-program = lualatex
\documentclass{article}
\usepackage{luacode} % for '\luaexec' macro
\newcommand{\myPerCent}[3][3]{\luaexec{%
tex.sprint( 100 * string.format("\%.#1g" , (#2)/(#3)) )
}\,\%}
\begin{document}
\myPerCent{2441}{8667}, \myPerCent[6]{2441}{8667}.
\myPerCent[1]{10/2}{2*3}, \myPerCent[5]{10/2}{2*3}.
\def\myten{10}\def\myfive{5} \myPerCent{\myfive}{\myten}.
\end{document}