They are both broken down into units & the unit 1 of the IG goes with unit 1 of the student workbook etc... Did you also get the DVD? Personally I didn't use the DVD or the IG until unit 9. Before that you are just doing numbers 0-9 & it is pretty self explanitory.
I've barely used the instructor's guide at all. I have found that the way I explain things seems to click with my daughter better. I've misplaced the DVD so we haven't used that in a few week either and she's still moving along just fine in the book.