nanna i u.s. dollars

I was double checking my answers for the math summer assignment last night and Google Suggest (Firefox) gave me a wrong (and totally nonsense) answer - “nannan i U.S. dollars” - for (5-pi)+(pi-5), while the result page returns the right answer: 0. (update: changed from 1, hehe)

Any idea what “nannan i U.S. dollars” might be?

UPDATE: It turns out that any expression with 0 as the answer will return “= nannan i U.S. dollars”. Thanks Ionut. :)