Hi, nhemker!

I think what you are asking is if progress you've already made (or your students) will "count" in mastery.  The answer is yes.  Mastery is an individual thing that keeps track of anything you've done.  It doesn't matter if you completed an assignment, worked on your own, did it with a different teacher last year, etc.  You can absolutely begin where you left off of topics.  By assigning mastery, it allows the teacher to see progress.

Hope this helps!

Amy

We've not used Kahn Acadmey this year, we used a new curriculum with workbooks.  Since Kahn Academy has my curriculum I'd like to assign the Eureka Math Mastery Course but am worried that if I set it up as Course Mastery instead of Assigned specific assignments they won't be able to just begin with where they left off in class... can they just skip to the section where we are, click on that module/topic/Lesson and begin working or do they have to start with Module 1 Lesson 1?

Got it.  Khan Academy will give blue buttons suggesting what to work on next.  But the choice is up to the user.  You would just need to make it clear what they should work on.

Another option is to have them scroll all the way down and start with the course challenge.  That would essentially allow them to "test out" of anything they already know and make Khan Academy's recommendations more relevant.