No, you absolutely don’t. We give you a book list in our Daily Lesson Plans and tell you how many and which weeks we use each book. You may substitute another book for one that is used less often. That is perfectly OK! Or, if you want to skip a book altogether, you may do that. However, the language arts (spelling, vocabulary, composition, and grammar) assignments are integrated into the main history and science reading. So we suggest skipping the books used just for reading, but not for language arts. However, that said, you can still effectively teach using different books – you may always follow our lead in the Daily Lesson Plans and develop similar lessons using your preferred book.