So far the biggest thing for me is organization. I have 4th grade curriculum in one area on my back counter. The 5th grade curriculum is right next to it. Having the two curriculums right next to each other really helps. I also ended up buying two Lesson Plan books. I tried to cram everything into one book, but the sections that they give you just aren't big enough to fit two grade levels in.
Wish me luck! I will keep everyone updated on the latest and greatest combo class!
Nicole