Total: 35 sessions worth of material. Answer key included. Original. * I erased as much as possible from the problem sheets, but I haven't erased the highlighting or red circles made with a highlighter. * I haven't erased any writing on the answer key/explanation sheets. I did a quick check, but please forgive any missing pages or incomplete answer pages. Since it was stored at home, there may be some minor stains. Please refrain from purchasing if you are looking for a perfect item. As this item is subject to copying, returns are not accepted after purchase. Thank you for viewing.