This is one in a series of wonderful Christian science books. These books are targeted for the junior high level, however, with a little help from the teacher they can be easily adapted for even a fourth grade level. These are not sufficient for high school level science though they would certainly be a good review prior to a high school level course. I would strongly recommend these books for the middle school age. We use these as summer science reading with some experiments. My son just finished fourth grade so he still needs some help but for the most part he can independently read, understand and answer the review questions. The books in this series could also be easily adapted to form a complete science curriculum.