# How do I rescale an align environment on a beamer slide?

I'm trying to resize an equation on a beamer slide to make it larger. However, the usual approach of using \scalebox doesn't seem to work:

\begin{frame}
\scalebox{2}{
\begin{align}
x &= y\\
y &= z
\end{align}
}
\end{frame}


Producing the following error:

! Missing \endgroup inserted.
<inserted text>
\endgroup


How do I rescale an align environment on a beamer slide?

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Add \Huge just before it? –  Torbjørn T. Mar 18 '14 at 6:15

align adjusts its contents based on the available width (in order to place it horizontally in the centre, and to place the appropriate tags/numbering). Inserting it inside a \scalebox causes the problem that there's no defined box to contain it. However, if you provide such a containment, it scales without problem:

\documentclass{beamer}% http://ctan.org/pkg/beamer
\usepackage{amsmath}% http://ctan.org/pkg/amsmath
\begin{document}

\begin{frame}
\begin{align}
x &= y\\
y &= z
\end{align}
\end{frame}

\begin{frame}
\scalebox{2}{\parbox{.5\linewidth}{%
\begin{align}
x &= y\\
y &= z
\end{align}
}}
\end{frame}
\end{document}

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+1 Off topic: I am curious why beamer.cls which is not a package is hosted in pkg directory of ctan.org? Theoretically it should be placed in ctan.org/cls. :-) –  kiss my armpit Mar 18 '14 at 6:35
@WeirdstressFunction: Yes. There are many such examples: IEEEtran, AMS-LaTeX - a collection of packages and classes, math-mode, texbook and TeX by Topic which are documents only, ... It may just be a database (filename) structure that they've stuck to in order to ease retrieval of information. –  Werner Mar 18 '14 at 6:42
@WeirdstressFunction "package" at ctan is a package in the sense of a package manager for linux (or tex live) a group of related files. The use is different (and predates) the use of "package" for latex which is a file containing a group of related commands. –  David Carlisle Mar 18 '14 at 9:58