apples

is there any quick way to convert numbers to fractions then back to decimals, without changing the mode.

also if i type in log 54, it gives me log 54.
i don't get an answer
even if i put in
ln 32
it gives me ln 32, not an answer.

i've learned to input functional equations and make graphs etc..
but can't really do a lot what i could do with my previous scientific calculator quickly.
help is appreciated.