Newbie Question: How Do You Set Default to Roll Up All SubProjects

[DeLaMartre]

Old Excel wiz here, but a Newbie to Project (and feeling very humble...). I want to set the default on my master project to have all subprojects (and sub-subprojects) roll up to the summary item above them. I am sure this is simple, but I would very much appreciate some advice.

Thanks very much for your time.

-Bob in California