Meaning of “number” - Learner’s Dictionary

number

verb [ T ] uk us /ˈnʌmbər/
GIVE A NUMBER

to give something a number:

[ often passive ] Each volume was numbered and indexed.
BE AN AMOUNT

If people or things number a particular amount, there are that many of them:

Our company's sales force numbered over 5,000.

(Definition of “number verb” from the Cambridge Learner’s Dictionary © Cambridge University Press)