No writing has been done. There is a crease on a page in the middle. (See the third image) --- A text with plenty of practice problems for elementary school students to develop mental calculation skills up to 19x19. - Title: The Book That Allows Elementary School Students to Mentally Calculate Up to 19x19 in Just One Day - Content: Abundant practice problems to get 100 points on calculation tests - Number of pages: 151 - Target age: For elementary school students - Features: Packed with ideas to improve speed, even for children who are not good at calculations Thank you for viewing.