Xu Zi: public information is limited, and the only known work is Junior High School Mathematics Week-by-Week Mastery, classified under exam preparation. Judging from the title and category, the book is aimed at junior high school mathematics learning and follows a week-by-week structure, helping students review and consolidate in step with their coursework. As supplementary teaching material, Xu Zi's writing tends to be practical, focusing on organizing key points and designing exercises to fit the pace of everyday study. Since the author's biography, nationality, and education are not available in the database, this profile makes no inferences and presents only the direction shown by the existing work: grounding in junior high mathematics, with an emphasis on staged, hands-on progress.
