In a tex document I have \textsc{exp3} and I would like to make the 3 a small caps number. Is it possible ?
Here is my code, which uses ACM template.
\documentclass[acmlarge]{acmart}
\settopmatter{printacmref=false}%
\renewcommand\footnotetextcopyrightpermission[1]{}%
\renewcommand\footnotetextauthorsaddresses[1]{}% \pagestyle{plain}
\fancyfoot{}
\makeatletter
\def\runningfoot{\def\@runningfoot{}}
\def\firstfoot{\def\@firstfoot{}}
\def\@copyrightspace{\relax}
\makeatother
\usepackage{amsmath}
\usepackage{amsfonts}
\usepackage{amsthm}
\usepackage{amssymb}
\usepackage[mathscr]{euscript}
\usepackage{booktabs} % For formal tables
\begin{document}
\title{My Title}
\author{Me}
\maketitle
\thispagestyle{empty}
This is my file. This is an algorithm, called \textsc{exp3}. Numbers like $1,2,3$ are not small caps.
\end{document}
See the figure below (the first set of numbers; from left to right):

\oldstylenums{3}. If you want it whenever small caps are used, I'd be inclined to usefontspec, but since I don't have to set a lot (any!) maths, I'm not sure how well that would play with what you are doing. – Paul Stanley Dec 19 '18 at 16:22