Math textbook using characters from Doraemon. - Title: Doraemon's Fun Math Strategies: Addition and Subtraction - Author: Fujiko F. Fujio - Price: 760 yen (excluding tax) - ISBN: 9784092531819 - Series: Doraemon's Study Series Thank you for viewing. I bought this for my child and kept it on the bookshelf. It's hardly been used, and while there's some soiling on the outside, there are no markings inside, and there's only age-related wear and tear, but it doesn't affect reading. (I tried to erase pencil marks with a black eraser, and the surrounding area is slightly darkened, as shown in the photo.) We appreciate your understanding if you are purchasing a used item.