In their attempt to be everything to everybody google has a calculator. I didn't know that until a couple of weeks ago when I put in the name of one of my units, 2/9, into a google search. Google first divided two by nine and then offered to do a further search. Pretty cool, I thought.
It also does long complicated problems for you. Let's say you drove your race car around the .533 mile speedway of Bristol TN and your average speed was 128.709 mph, how many seconds would it take you to complete a lap? Let's let google do it for us.