[Tex/LaTex] “Missing Delimiter” in Beamer-class

delimiterserrors

I got a problem when trying to change the fontsize within a beamer-class frame.

\documentclass{beamer}
\begin{document}
\begin{frame}{First frame}
{\big Just some content} 
\end{frame}
\end{document}

This gets me a "missing delimiter (. inserted)" error. What's the problem with this? I'm using the pdfLaTex compiler.

Thanks a lot!

Best Answer

Andrew Stacey provided the answer: \big belongs to math-mode and is defined by amsmath which is loaded automatically by beamer, I was looking for something like \huge or \large.