Well to be a bit more accurate than renee12, it's 6.6 repeating, as in, after the decimal, it's an infinite number of 6's.
And to provide you with further information, you're sitting at a computer, and all current operating systems (even most dated ones too). If you're running any Windows based operating system, just check the Start menu, and check Accessories. If you're running a Macintosh based operating system, check the Applications folder in the Hard Drive. If you're on Linux, well, you should know what you're doing with Linux and thus should know where the calculator is at least.