% This picture represents the natural number line
% (C) Thiago Brevidelli
\begin{tikzpicture}
  % The line
  \draw[-latex] (0,0) -- (6, 0) node[right]{$\mathbb{N}$};

  % The the numbers
  \foreach \x in {0,1,2,3,4,5}
  \draw[shift={(\x,0)}] (0,3pt) -- (0,-3pt) node[below]{$\x$};
\end{tikzpicture}