Square root

${\begin{array}{r|rrr}&2&5&\\\hline {\sqrt {}}&6&55&36\\{\underline {2}}\times {\underline {2}}=4&-4&\downarrow &\\\hline &2&55&\\4{\underline {5}}\times {\underline {5}}=225&-2&25&\downarrow \\\hline &&30&36\end{array}}$

to be continued