A family of Microsoft word processing software products for creating web, email, and print documents.
The way you have found is the way I would do it: it probably is the easiest.
However, there are several other methods described here:
http://word.mvps.org/faqs/numbering/ListRestartMethods.htm
I use a variation of the "VBA" method, to ensure we get the same list re-applied each time.
Some people are very fond of the "Restart on higher..." method, which is "automatic".
I personally don't use that method except in extremis, because it confuses unskilled people who may be working on the document later, in which case they will break the list and the numbering in the entire document will instantly go wrong!
Hope this helps