I study the brain, the organ responsible
for Beethoven's "Fifth Symphony."
The Big Bang Theory Season 4, Episode 24
You, uh, moving into the apartment
on the FIFTH floor?
The Big Bang Theory Season 6, Episode 8
There's only three people in this house,
and you'd still be my FIFTH guess.
The Big Bang Theory Season 10, Episode 10
but I spent most of FIFTH grade
with my head in a toilet.
The Big Bang Theory Season 7, Episode 2
...to be picked for a game in FIFTH grade,
I'm sure you do suck.
The Big Bang Theory Season 8, Episode 3