# Where are all these errors coming from?

With the following document, I get a lot of errors around line 38. I can't tell where these come from, but the resulting output looks fine. For the sake of good practice, what am I doing wrong here?

\documentclass{beamer}
\renewcommand\arraystretch{1.2}
\usepackage{beamerthemesplit}

\title{Why Duodecimal is Better than Decimal\\
(Yes, really.)}
\author{Alex Stubbins}
\date{\today}

\begin{document}

\frame{\titlepage}

\section{Introduction}
\subsection{}
\frame{
\frametitle{What is duodecimal?}
Duodecimal, less commonly referred to as dozenal, is a number system that has a base of twelve, whereas our standard number system, decimal, has a base of twelve.
}
\frame
{
\frametitle{Fractions}\begin{table}
\begin{tabular}{|c|c|c|}
\hline
Fraction       & Base-12                                 & Base-10             \\ \hline
$\frac{1}{2}$  & 0.6                                     & 0.5                 \\ \hline
$\frac{1}{3}$  & 0.4                                     & 0.\overline{33}     \\ \hline
$\frac{1}{4}$  & 0.3                                     & 0.25                \\ \hline
$\frac{1}{5}$  & 0.\overline{24972497}~or~$\approx$~0.25 & 0.2                 \\ \hline
$\frac{1}{6}$  & 0.2                                     & 0.1                 \\ \hline
$\frac{1}{7}$  & 0.\overline{186A35}                     & 0.\overline{142857} \\ \hline
$\frac{1}{8}$  & 0.16                                    & 0.125               \\ \hline
$\frac{1}{9}$  & 0.14                                    & 0.\overline{1}      \\ \hline
$\frac{1}{10}$ & 0.\overline{12497}                      & 0.1                 \\
\hline
\end{tabular}
\end{table}
}
\end{document}


The resulting errors are:

Log can be seen here

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Welcome to TeX.SE, and thanks for providing a compilable MWE. –  Peter Grill Nov 21 '12 at 3:14

Since this question is about "learning", here are some suggestions:

• \overline requires math mode, so you need to brace it with $...$;
• Tables look awesome when using the booktabs package;
• Consider using the environment form of frame, so \begin{frame}...\end{frame} rather than \frame{...};
• Since you're using predominantly math in the tabular, rather use an array environment. This requires non-math elements to be in text mode. I've used \textrm below, although you might consider using something like \textsf since the document style is written in a sans-serif font; and
• There's no requirement to use a table (floating) environment in a presentation, or anywhere for that matter, if you don't have an accompanying caption. So, rather avoid it here.

\documentclass{beamer}% http://ctan.org/pkg/beamer
\renewcommand\arraystretch{1.2}
\usepackage{beamerthemesplit,booktabs}% http://ctan.org/pkg/booktabs

\title{Why Duodecimal is Better than Decimal\\
(Yes, really.)}
\author{Alex Stubbins}
\date{\today}

\begin{document}

\frame{\titlepage}

\section{Introduction}
\subsection{}
\begin{frame}
\frametitle{What is duodecimal?}
Duodecimal, less commonly referred to as dozenal, is a number system that has a base of twelve, whereas our standard number system, decimal, has a base of twelve.
\end{frame}

\begin{frame}
\frametitle{Fractions}

$\begin{array}{ccc} \toprule \textrm{Fraction} & \textrm{Base-12} & \textrm{Base-10} \\ \midrule \frac{1}{ 2} & 0.6 & 0.5 \\ \frac{1}{ 3} & 0.4 & 0.\overline{33} \\ \frac{1}{ 4} & 0.3 & 0.25 \\ \frac{1}{ 5} & 0.\overline{24972497}~\textrm{or}~\approx 0.25 & 0.2 \\ \frac{1}{ 6} & 0.2 & 0.1 \\ \frac{1}{ 7} & 0.\overline{186A35} & 0.\overline{142857} \\ \frac{1}{ 8} & 0.16 & 0.125 \\ \frac{1}{ 9} & 0.14 & 0.\overline{1} \\ \frac{1}{10} & 0.\overline{12497} & 0.1 \\ \bottomrule \end{array}$
\end{frame}
\end{document}

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Thank you so much. That worked perfectly. –  Nonya Bizness Nov 21 '12 at 4:03

The \overline{} need to be used in math mode.

Furthermore, numbers should usually be in math mode (important if you have negative numbers), and since most of our table has numerical content you could just use the array environment and use \text{} to go out of math mode for the titles. I have adjusted the code below to use array:

## Code:

\documentclass{beamer}
\renewcommand\arraystretch{1.2}
\usepackage{beamerthemesplit}

\title{Why Duodecimal is Better than Decimal\\
(Yes, really.)}
\author{Alex Stubbins}
\date{\today}

\begin{document}

\frame{\titlepage}

\section{Introduction}
\subsection{}
\frame{
\frametitle{What is duodecimal?}
Duodecimal, less commonly referred to as dozenal, is a number system that has a base of twelve, whereas our standard number system, decimal, has a base of twelve.
}
\frame
{
\frametitle{Fractions}\begin{table}
$\begin{array}{|c|c|c|} \hline \text{Fraction} & \text{Base-12} & \text{Base-10} \\ \hline \frac{1}{2} & 0.6 & 0.5 \\ \hline \frac{1}{3} & 0.4 & 0.\overline{33} \\ \hline \frac{1}{4} & 0.3 & 0.25 \\ \hline \frac{1}{5} & 0.\overline{24972497}~\text{or}~\approx~0.25 & 0.2 \\ \hline \frac{1}{6} & 0.2 & 0.1 \\ \hline \frac{1}{7} & 0.\overline{186A35} & 0.\overline{142857} \\ \hline \frac{1}{8} & 0.16 & 0.125 \\ \hline \frac{1}{9} & 0.14 & 0.\overline{1} \\ \hline \frac{1}{10} & 0.\overline{12497} & 0.1 \\ \hline \end{array}$
\end{table}
}
\end{document}

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