I will have an 11th grader, a 9th grader, and a 4th grader next year. Can I jump in this late in the game with a 11th grader? He wants to graduate early and I know he needs credits in American History, GOVERNMENT AND Economics. Is it too late to jump in with him? And what about the 9th and 4th graders? We have done more world history with the 4th grader and the 9th is starting, well....fresh for high school. Should I continue to just do my own studies?