When I were in Japan and went to some bars, I often saw, that the drinks in menu were numbered, and I also heard someone ordering something from the menu with words “一番”. And so, I started ordering drinks by numbers, for example, if I wanted a drink by number 5, I would say “五番” (also wanted to say something like “おねがいします”, but was not sure, that it was appropriate, when ordering something in a bar). Recently I stumbled upon construction “一番目” in wanikani, which has similar meaning.
And so, now I am confused, what is the right way to order something in a bar with menu, where positions are numbered?