\begin{tikzpicture}[scale=\textwidth/10cm,samples=200]
\draw (0,0) grid (7,5);
\foreach \ytick in {1,...,5}
	\foreach \xtick in {1,...,7}{
		\pgfmathsetmacro\result{\xtick + 7*(\ytick-1)} 
		\node at (\xtick - 0.5,6-\ytick-0.5) {\pgfmathprintnumber{\result}}; 
}

\end{tikzpicture}