Repeating Decimal as a Fraction

0.6464... (repeating) as a Fraction?

$\begin{array}{|rcll|} \hline 1\cdot a &=& 0.6464... \text{ (repeating)} \\ 100\cdot a &=& 64.6464... \text{ (repeating)}) \\\\ 100\cdot a - 1\cdot a &=& 64.6464... \text{ (repeating)} - 0.6464... \text{ (repeating)}\\ 99\cdot a &=& 64 \\ a &=& \frac{64}{99} \\ \mathbf{ 0.6464... \text{ (repeating)} } &\mathbf{=}& \mathbf{ \frac{64}{99} }\\ \hline \end{array}$