Well, the whole thing really doesn't make much sense to me. Since I'm not sure what context he was speaking in, I don't even know what he is talking about. Because you were watching a video, I will assume that what you were reading were automated subtitles. If I am correct, then you can rest assured that many times automated subtitles make mistakes (I have noticed that MANY times). Yet, since I cannot know for sure, here is a quote from GrammarBook.com:
Single-digit numbers are usually spelled out, but when they aren't, you are just as likely to see 2s and 3s as 2's and 3's. With double digits and above, many (but not everyone) regard the apostrophe as superfluous: I scored in the high 90s.
If you can give more information, people may be better equipped to give you a specific answer.