expression
nothing special; not a big deal; insignificant
Used to dismiss something as trivial, unimportant, or not worth counting. Often appears in negative contexts to emphasize that something is negligible.
これくらいの失敗は物の数ではない。
A mistake of this level is nothing to worry about.
彼にとって千円くらいは物の数ではない。
To him, about a thousand yen is insignificant.
Both mean 'insignificant,' but 取るに足らない is more formal and often used in written language, while 物の数ではない is a colloquial expression.
Literally 'it is not the number of things,' meaning something is so trivial it doesn't even count as a thing. The exact origin is uncertain, but it is a common idiomatic expression.