Helium has
an atomic NUMBER of two.
The Big Bang Theory Season 7, Episode 3
Rule NUMBER two in a marriage:
The Big Bang Theory Season 12, Episode 5
He really did a NUMBER on you,
didn't he?
Breaking Bad Season 5, Episode 11
This is my NUMBER.
The Big Bang Theory Season 5, Episode 7
It's useful for calculating the NUMBER
of atoms in a substance,
The Big Bang Theory Season 9, Episode 10