Translation:We are on the third floor, not the second.
jianzhiw, tercero seems to be one of those adjectives which drop the final "o" before a masculine noun. See http://elblogdegramatica.blogspot.com/2012/11/definicion-de-apocope-ejemplos-de.html
I think "We are on the third floor, not the second one" should also be accepted.
I'd agree that it should if only "ate" were spelled "are."
(Then I'd say "... Could also be accepted.")
Sure, I meant "are". Sorry for mistyping. It is hard to type on the mobile screen in a bus :)
28.07.2108 "we are on the third floor not on the second" rejected. reported. But google translate gives "estamos en el tercer piso, no en el segundo". for the above phrase, and agrees with DL. that without the "en" "no el segundo" signifies simply "not the second" . Moving on...