Sooo...yes there are some really cool looking models in this book. And yes they are cumulative so that when you are done you can lie on the floor with your anatomy on top of your clothes and look really gross/cool, like an anatomical model. But when you read the the simple directions ( sometimes just a few steps) they say "paint it as shown" (a beautifully rendered detail painting of the interior of the four chambers of the human heart, with valves and muscle striations, all unlabeled), "cut out the skull shape" (The cream on white photo of the shape is perhaps 1/10th the needed size and very complex, and they want me to eyeball it!? No, they provide the hint that I might trace this nearly invisible complex shape with tracing paper and then blow it up on a photo copier.) Basically the idea is: here is a single picture of a cool 3D project, kids, with a basic parts list. Now copy it! Which seems like a recipe for frustration, or a great idea for a science fair project for the right kid, but don't expect a rewarding afternoon with your family doing a heartwarming science lesson like a casual homeschool mom. These are major art projects with almost no guidance.
While other science books may have projects where you need chemicals, this is one of those books which has projects that you can do with kid-friendly art supplies. And that just goes to show that teaching science doesn't have to be so costly.