\[\boxed{\mathbf{894\ (894)}.\ Еуроки\ - \ ДЗ\ без\ мороки}\]
\[1)\ (12,82 + 8,394) + 5,18 =\]
\[= (12,82 + 5,18) + 8,394 =\]
\[= 18 + 8,394 = 26,394\]
\[2)\ 2,53 + 15,1 + 4,47 + 14,9 =\]
\[= (2,53 + 4,47) + (15,1 + 14,9) =\]
\[= 7 + 30 = 37\]
\[\boxed{\mathbf{894}.\ }\]
\[1)\ \frac{5}{7}\]
\[2)\ \frac{19}{4}\]
\[3)\ \frac{1}{6}\]
\[4)\ \frac{30}{4}\]
\[5)\ \frac{6}{1}\]