Entering the wonderful world of mathematics 1-3 (a set of 3 volumes) is one of the most classic works of Yasuya Anyo, winner of the International Andersen Prize and author of travel picture books. Each volume of this book 104 pages (4-5 chapters, each focusing on a mathematical idea). It breaks the impression that mathematics is boring and rigid, integrates science and art, and draws exquisite pictures carefully, so that children can appreciate the double aesthetic feeling of science and art. Moreover, each book is accompanied by explanatory words written by Yasuya Yasuo Yasuo, which supplements the mathematical knowledge involved in detail and has strong extensibility and enlightenment.