Modern Greek has borrowed duzina from Venetian, so that does get used.
What is more idiomatic is the suffix –arja added on to tens-words, meaning “approximately”. So ðekarja “around ten”, triantarja “around thirty, thirty-odd”, eksindarja “around sixty, sixty-odd”.
[EDIT: correction to hundreds]
Also ðjakosarja “two hundred-odd”, triakosarja “three hundred odd”, up to enjakosarja “nine hundred-odd”; “one hundred-odd” is (e)katosti or katostarja.