Square root that is close to 7
$${\sqrt{{\mathtt{49}}}} = {\mathtt{7}}$$ can't get much closer than that :)
$${\sqrt{{\mathtt{7}}}} = {\mathtt{2.645\: \!751\: \!311\: \!064\: \!590\: \!6}}$$
$${\sqrt{{\mathtt{50}}}} = {\mathtt{7.071\: \!067\: \!811\: \!865\: \!475\: \!2}}$$