\[\boxed{\mathbf{268}\mathbf{.}}\]
\[1)\log_{2}\frac{1}{2} = \log_{2}2^{- 1} = - 1\]
\[2)\log_{2}\frac{1}{8} = \log_{2}\frac{1}{2^{3}} =\]
\[= \log_{2}2^{- 3} = - 3\]
\[3)\log_{2}\sqrt{2} = \log_{2}2^{\frac{1}{2}} = \frac{1}{2} = 0,5\]
\[4)\log_{2}\frac{1}{\sqrt[4]{2}} = \log_{2}\frac{1}{2^{\frac{1}{4}}} =\]
\[= \log_{2}2^{- \frac{1}{4}} = - \frac{1}{4} = - 0,25\]