# Centering a enumerate list label

In this code as here:

\begin{enumerate}[label=\bfseries Exercise \arabic*:]
\item 5 + 7 = 12
\item 9 + 1 = 10
\item 2 * 2 = 4
\end{enumerate}


I want the text Exercise (with its number) to be center-align and the content after that to be below and left-align. Anybody can help. Thanks.

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You mean so that \item 5 + 7 = 12 translates into "Exercise 1 <newline> 5 + 7 = 12". Or is each enumerate block prefaced by the Exercise ? – jon Feb 12 at 4:08
@jon I mean: Exercise 1 <newline> 5 + 7 = 12 – Exdata Feb 12 at 4:21

Here is one way to achieve the desired results:

## Improvements

• Note that there is a -5.0pt tweak to the labelwidth to compensate for the with of the label. This really should be computed based on other enumitem lengths.

## Code:

\documentclass{amsart}

\usepackage{enumitem}
\usepackage{showframe}

\SetLabelAlign{center}{\hss#1\hss}

\begin{document}
\begin{enumerate}[label={\bfseries Exercise \arabic*},
align=center,
labelwidth=\dimexpr\linewidth-5.0pt\relax,
leftmargin=!,
style=unboxed,
]
\item 5 + 7 = 12
\item 9 + 1 = 10
\item 2 * 2 = 4
\end{enumerate}
\end{document}

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Thank Peter Grill and Andrew very much. This helps resolve my problem. But I don't understand why you can add those things. What lines in what pages in what documents you use for the added code above. I have read over and over enumitem documentation but I can't resolve the problem. You two great! – Exdata Feb 12 at 8:03
@Exdata: This really is not what lists are intended for thus I think it'll be difficult to find such an example in the documentation. But you could search the enumitem documentation for \SetLabelAlign where there is a related example without the second hss and meaning of labelwidth. – Peter Grill Feb 12 at 8:06

Why in an enumerate environment? I might be inclined to cheat if that is the input (though I hope it is not if you are actually typesetting math).

\documentclass{article}
\usepackage{lipsum,showframe}

\newcounter{exercise}
\setcounter{exercise}{0}
\renewcommand{\theexercise}{\arabic{exercise}}
\newcommand\iitem[1]{%
%\begingroup
\refstepcounter{exercise}%
\parindent0pt
{\centering
\textbf{Exercise \theexercise}\par} #1%
%\endgroup
}

\begin{document}

\section{S One}

\lipsum[1]%\label{zzz}

\iitem 5 + 7 = 12

\iitem 9 + 1 = 10

\iitem 2 * 2 = 4\label{asdf}

See Exercise \ref{asdf}.
\lipsum[1]

\end{document}


Of course, as soon as you want to include real math, you're going to need far more robust commands....

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