% This picture represents the real number line
% (C) Thiago Brevidelli
\begin{tikzpicture}
  % The line
  \draw[latex-latex] (-3,0) -- (3,0) node[right]{$\mathbb{R}$}; 

  % The numbers
  \foreach \x in {-2,-1,0,1,2} 
  \draw[shift={(\x,0)}] (0pt,0pt) -- (0pt,-3pt) node[below]{$\x$};

  % A real number x between 0 and 1
  \draw[shift={(0.6,0)}] (0pt,6pt) -- (0pt,-6pt) node[below]{$t$};
\end{tikzpicture}