Best-selling calculation materials. This is a set of 4 books from the Thorough Repetition/Kageyama Method for Kids series. With these 4 books, my child has completely mastered the concepts. I highly recommend them for repetitive practice. ● First Addition ● First Subtraction ● First Addition with Carrying Over ● First Subtraction with Borrowing List Price: 700 yen each (2,800 yen total) - Not sold separately. - No writing inside. - Please refrain from purchasing if you are concerned about minor details, as this is a personal inspection and storage.