I am currently using Sonlight Core D+E with my 3rd and 5th grader. They are together for all the history, geography, read-alouds, and Bible. I teach them separately for all other subjects, including independent reading. This allows for group discussions as well as individual, leveled work time. In order to keep one child from dominating our group discussions, I give each of them questions & have them take turns answering. I also expect more from the older child when I assign history reports or projects, but my younger one sees what my older one is doing & often challenges himself.:)