My son took this class, "College of the Redwoods" PreAlgebra, when he was 12. I DO NOT recommend this text. When this son was 9, he won the city-wide elementary homeschool math contest. His brother, who is now 9, just today, took second place in the city wide (not just homeschool) grade 4 math contest. He had never had any big issues with math until this book. This is a book for people in college who are going NO FURTHER in math but need a college level math credit to satisfy the requirements of whatever program they are in. This is the opinion of my children's father, who has a PhD in Mathematics. I am only a lowly Honors Math / Electrical Engineering undergrad........but .... I agree with him. :-) This book seemed very confusing. Beyond which, if you do not answer the questions in "their" overly complicated way, you get it "wrong". We love Math Mammoth http://www.mathmammoth.com/ and AOPS http://www.artofproblemsolving.com/ I have also heard good things about "Singapore Math". Hope this helps someone! Stephanie