We also have a separate case for missing something. So it's "Mam 3 książki" (I have 3 books) but "Nie mam 3 książek" (I don't have 3 books) or "Brakuje 3 książ

We also have a separate case for missing something. So it's "Mam 3 książki" (I have 3 books) but "Nie mam 3 książek" (I don't have 3 books) or "Brakuje 3 książek" (3 books are missing).