\[\boxed{\text{6.464.}}\]
\[10,7 - 2,3 = 8,4\]
\[8,9 - 5,7 = 3,2\]
\[2,11 + 1,04 = 3,15\]
\[2,34\ :0,39 = 234\ :39 = 6\]
\[6 \cdot 8,4 = 50,4\]
\[50,4\ :10,08 = 5040\ :1008 = 5\]
\[5,52\ :0,69 = 552\ :69 = 8\]
\[9,9 - 8 = 1,9\]
\[8,1 + 1,9 = 10\]
\[5 - 0,125 = 4,875\]
\[3,7 + 0,05 = 3,75\]
\[4,875\ :3,75 = 487,5\ :375\]
\[1,3 \cdot 10 = 13\]