If you search Google for a simple question with a concrete, factual answer, it will give that answer ahead of all the usual links.
For example, I just put in 'how many square feet in an acre' and got '1 acre = 43 560 square feet'. Thanks, that's what I needed, bye. Other recent applications include comparing the land areas of Maryland and El Salvador. El Salvador is twice as big. And the Earth weighs 5.98x1024 kilos.