I have actually only begun to use this product. After looking through it, I like what I see. However, it is centered around little booklets and pamphlets that the kids create to help them learn the concepts. The authors tell you to either cut up the masters that are in the book, or to make copies of them for multiple students. However, the pages are not perforated and the binding on the book is extremely stiff. Since it is very important that the front and back line up exactly in order to create a neat book, it is nearly impossible to make usable copies without tearing the pages out of the book. But the lack of perforation makes this a risky prospect. Not to mention that I prefer to keep my book whole! This really should have be a spiral-bound book, or at least should have been created with a much softer binding.