This is a third grade classroom science kit. I have used it in homeschool for grades 1-3. It only has two of each concept (lesson) card instead of 4. It has everything else complete. For some reason the box is very big so I used the extra room to add more own supplementary materials. My kids loved this science program because it is short and to the point. When we had extra interest we could study further, but if not then we were done. Everything is in wonderful condition. Pet free, smoke free, nice clean home. Cash only.