I used this book to study for the Compass test. The functions part of the test confused me because they wrote them different than the book showed. (I thought math never changed). Very helpful--I am keeping it to help my son when he takes it in the next couple of years. Side note--Do everything you can to keep your schools from implementing Investigations, Connected, or Fuzzy math!! These programs have messed up my kids and have no place in our education system!