Google has added a calculator function to its search engine. Just type in something like 2+2 and it will do the math for you. It is very powerful though as well. You can type "12 feet in furlongs" and it will figure that out too. It can even do this...
(G * mass of earth) / (radius of earth ^ 2)
I'm pretty impressed.
(G * mass of earth) / (radius of earth ^ 2)
I'm pretty impressed.