Of or Off ?
Exemple : ‘’There are four of them in the box.’’
"Of" and "off" are two words in the English language which are commonly misused by both native and non-native speakers alike. "Of" is a preposition which is used in order to denote possession, amount or origin.
Exemple : ‘’I am going to take off my make-up now.’’
"Off" is an adverb which is used as a synonym of the phrase "away from."