Actually, declining numbers is something most native Russian speakers can't do. Even people on TV, whose job is to speak correctly, often struggle with it. More

Actually, declining numbers is something most native Russian speakers can't do. Even people on TV, whose job is to speak correctly, often struggle with it. Moreover, in the Russian translation of the Empire Strikes Back, C3PO's line "Sir, the possibility of successfully navigating an asteroid field is approximately three thousand seven hundred and twenty to one" has the number declined a wrong way.