I’m a pedant, which means I get really annoyed really quickly when people make little mistakes. The one I’m going to elaborate on today is the misuse of “amount” and “number”.
You don’t have an amount of people. You have a number of people. (Say them both; see which one feels more natural.) You don’t have a number of flour. You have an amount of flour, e.g. 3oz, or whatever other measuring system you prefer. And here is the difference: an amount deals with a pile, and number deals with a distinct, well, number.
So get it right! (Also feel free to find esoteric examples to prove me incorrect in some cases. :)