You're using the wrong slash. ;-) What you really want is this:
The other slash, '\' is used to tell the shell that you aren't finished typing this line yet, so keep reading just like you haven't pressed ENTER.
$ cd \ [ENTER]
> / [ENTER]
Obviously don't type the [ENTER] part, that's where you hit the ENTER/RETURN key.
You can learn more about the cli by going here: