\[\boxed{\text{6.366.}}\]
\[9 - 5,3 = 3,7\]
\[1,89 + 1,51 = 3,4\]
\[5,4\ :2,7 = 54\ :27 = 2\]
\[0,96\ :2,4 = 9,6\ :24 = 0,4\]
\[2 + 0,4 = 2,4\]
\[0,78\ :3,9 = 7,8\ :39 = 0,2\]
\[1,2 - 0,2 = 1\]
\[1\ :0,125 = 1000\ :125 = 8\]