Apologia’s books are not living books in the CM sense of the word, however they are written in a conversational style. They present all scientific terminology and at least the upper level books are very thorough in presenting the material. I have a strong science background and I have been impressed with the material covered in the books.
Though you may be able to find some good living books covering some of the material taught in biology, it would be very difficult to find living books on chemistry, for example. As far as the General Science and Physical Science books are concerned, the material covered in each of these books is very general. If you have been very broad in your living book selections for science to this point, then these books will probably be mostly review. They do introduce some scientific terminology that is not usually presented in living books. So, if learning the correct terminology is important to you, you should start with at least the Physical Science book.
You can easily fit them into the CM style by continuing to read living books. You may not be able to find living books that correspond with the material being taught but that shouldn’t stop you from enjoying living books!
If your child is planning on attending college, then I highly recommend that he complete a course in at least biology, chemistry, and physics. However, if your child has no plans for college then continuing with just living books and maybe some experiments might be okay. That is entirely up to you and what your state requires.
I know that the books can be expensive but they are non-consumable and can be used for all the kids in a family. The cheapest place to buy them right now is Christian Book Distributors.
Hope that helps.
