I know that you can do this from the menu or ctrl+9 and so on, but I seem to remember in a class that we were able to have little plus and minus symbols appear on a sidebar near the beginning of the range and all you had to do was click on them to show or hide the range. It was really convenient and really visually unconfusing. IIRC, it was a combo of two or three keys that enacted this feature.
I have Office 2000, not entirely sure what we were using in class, that may be the problem.
Thanks.