%% 
%%  A DANTE-Edition example
%% 
%%  Example 02-24-1 on page 99.
%% 
%%  Copyright (C) 2010 Herbert Voss
%% 
%%  It may be distributed and/or modified under the conditions
%%  of the LaTeX Project Public License, either version 1.3
%%  of this license or (at your option) any later version.
%% 
%%  See http://www.latex-project.org/lppl.txt for details.
%% 
%% 
%% ==== 
% Show page(s) 1
%% 
\documentclass[]{article}
\pagestyle{empty}
\setlength\textwidth{201.70511pt}
\setlength\parindent{0pt}

\usepackage{dcolumn}

\begin{document}
\begin{tabular}{| c | D{.}{,}{5} | D{,}{.}{-1} | }
\textit{name}& \textit{value} & \textit{standard form}\\\hline
 e & 2.71828 & 0,271828\cdot10^{1}\\ $\pi$ & 3.1416 & 0,31416\cdot10^{1}\\
 v & 0.21    & 0,21               \\    Q  & 0      & 0
\end{tabular}
\end{document}