Robert,
Thank you so much for your thorough and helpful answer. Both of us had read up on it, but missed the point that validation happens in a diff, more manual, way than for coded value domains, where we get a pick list of allowable choices. With your help, we are pleased to be able to set the option for automatic validation, via: Customize - arc map options - check the box for "auto validate records when editing" and then get the warning message when we enter a number outside of our range. Only in an editing session.
We are really grateful for your help.
Ken