From Förberedande kurs i matematik 1

If we divide \displaystyle 243 successively by \displaystyle 3, we see that

\displaystyle \begin{align} & 243=3\centerdot 81=3\centerdot 3\centerdot 27=3\centerdot 3\centerdot 3\centerdot 9 \\ & \\ & =3\centerdot 3\centerdot 3\centerdot 3\centerdot 3=3^{5} \\ \end{align}