This is the "Original Text" from Mori no Mi Publishing, a textbook specifically for cram schools. It's a well-regarded textbook for solidifying the basics. As it's a collection of basic-level problems, I think it's suitable for home study. Original Text for grades 3-6 is currently available. I also have other "Elementary School Textbooks" for sale. #hiroko_elementaryschooltextbooks (← Link to my listings) I also have "Middle School Textbooks," "University Entrance Exam Textbooks," "Mathematics for University," and "Dictionaries" for sale. Please understand that these items are stored by a private individual, so there may be minor scratches or stains from storage. This is the latest edition of the arithmetic problem book and is in unused condition. - Title: Original Text Elementary School 4th Grade Arithmetic - Edition: Latest Edition - Condition: New, Unused - Contents: Arithmetic Problem Book Thank you for looking.