This is not your regular search engine,  this is a computation engine that I have used in the past. Today I went on to this website and started using it for studying that I needed to keep up with school I got going on,  I love the website and I'm using the 14 day trail pro version, which I like but I know it still needs some work to be added like historic events from world history but over all it's a great site to search for knowledge and facts and very similar to Wikipedia, the thing that separates a search engine like Google and Yahoo and a free Encyclopedia that its neither,  Its a knowledge computation engine to search up facts quickly than a search engine that you normally do.  Example let's say if you're trying to look for a math question all you have to do is type answer down to the search bar and it'll compute the answers within seconds you get it in no time!  it's pretty quick and one of the Internets hidden gems that you may not know about. I discovered it few years ago while the company was born 2009 when it was announced a press conference showing presentation on how the knowledgeable engine works.  So for anyone that's need help on Science, Social Studies or Math it's for anyone that's in a Middle School, High School or at a College Level.  (it can also be use in a Elementary level). 

http://www.wolframalpha.com/