This book is nice if you are teaching multiple grades at the same time. "The Human Body" book has depth and vocablulary that is very well suited for grades 1-6. I do think if you were using it for anyone above 6th grade, you would possibly need to supplement with other material. I'm using it with my 5th and 2nd graders and I am using some of the "6th-8th grade" boxes with my 5th grader. I was disappointed that I had to buy the Teacher Supplement seperate to get the worksheets that are mentioned in the book. Overall my kids are enjoying the book and so am I.
The God's Design for Life series from Answers in Genesis is a Bible-based science curriculum with solid science. The Human Body covers the five senses, the major body systems, nutrition, and much more, and presents the material at an appropriate level for the elementary years. It has interesting activities, nice photos and diagrams, and glorifies God as Creator of the human body. Overall, the God's Design series is the best elementary science series that I've seen.
The idea behind this series is wonderful; unfortunately, the execution fails miserably. The revised version while tremendously better than the original is still a complete waste of money. The depth is about right for a 1st - 3rd grade level. The experiments, and that term is used very loosely with these books are usually cheesy, even to kids. The work that it would take to adapt these books to use for a child above the 3rd grade would be tremendous and the end result would be that you maybe used the table of contents as an outline. Even though the depth is appropriate for around the 1st - 3rd grade level the interest and fun really isnt there. While these books are written from a Christian perspective even that isnt done as well as it could or should be. Please dont waste your money these. For children in 4th - 8th grade there is a wonderful series that includes Exploring the World of Physics, Exploring the World of Biology, and others. These are wonderful, interesting, factual, Christian science books. Bob Jones and Apologetics are also excellent choices for all grade levels.