I guess I didn't make myself clear. What I meant was "chapter numbering" (since each chapter appears on a web page). Choosing "numbering" as the "chapter numbering" setting doesn't allow for adding a preface "chapter" before the numbering starts. I've got a book I am creating that is tied to a actual real life textbook, but I want to write my own introduction to it.
You can disable chapter numbering and type chapter numbers manually 
That is true, I thought of that. But there was some reason that wasn't entirely satisfactory. Problem is, I can't recall why it was unsatisfactory. If I do remember, I'll let you know.