What is 6.5 in binary? I just stumbled across a problem I never actually thought about before: decimals in binary. Can someone explain how to do it? Thanks!
Note: If possible, I'd like the answer in decimals not fractions, but this may not be possible.

"decimals" in other bases are done the same way as regular decimals:  just as $6.5 = 6\frac{5}{10}$, $110.1_2=110_2\frac{1_2}{10_2}=6\frac{1}{2}$.
Similarly, $5.25=5\frac{1}{4}=110_2\frac{1_2}{100_2}=101.01_2$.
