I meant to mention something about this when I posted our Education Plan. I use what I call the "Trickle Down Effect" in our home school. When I'm deciding what to do with my younger students for subjects like Science and Social Studies I always start with my oldest and "trickle down". In other words, whatever the oldest child is studying in a particular year determines what I will be doing with the younger ones. For example, my oldest (16) is studying Chemistry and U.S. History this year, so for Science the younger kids will have Chemistry, and for Social Studies they will study U.S. History. It helps me to simplify things a bit if I am able to combine subjects. Obviously my seven year old and my 16 year old will not have the same Chemistry book or the same tests and quizzes, but there are areas that overlap. While I am teaching an older student a particular subject it is amazing what the younger students will glean. I have found this method to be very helpful.