Bought this book to do our science unit on DINOSAURS. I have some other books from the public library, but they were all full of fanicful notions about dinosaurs living millions of years ago, etc. etc. I appreciate our state laws here in Missouri on homeschooling. I do 1,000 hours annually, 600 of which must be "core" (reading, English, social studies, math, science) and 400 of whatever electives I choose if I wish. I think we'll wind up with only 300 hours of electives and maybe 950 in core at the rate we're going... but only 1,000 required total. No registration. No tests. The state only gives me the GUIDELINES that say how many core hours to teach per year. They do NOT dictate my curriculum. I could teach a first-grader high school math if I wished, or vice versa. When you think about it, would you have it any other way? Would you want the state to dictate what must be learned by each child and by what age? I am very grateful for the freedom we have in Missouri to teach whatever we wish to our children. Incidentally, I like this book very much. I'll have to write a review of it later as we progress through it.