This second edition includes updates on relevant topics as well as stylistic changes. The primary function of the appendix (discovered in 2006) has now been included, as have higher-quality drawings and more colorful illustrations. Online resources for advanced students and a review appendix have also been included in this 2nd edition. This kit contains both the student textbook and test/answer key booklet. Grade 7, but may be used with younger/older students as parents see fit.