Not difficult. The mathematical knowledge in Li Yupei's Adventures in Mathematics is relatively simple. This paper mainly summarizes the mathematical knowledge points involved in the story according to the readers' mastery of mathematical knowledge and thinking ability in the fourth, fifth and sixth grades of primary schools, and matches them with fun tests for young readers to practice. In this book, each story deduces a mathematical problem, turning abstract and blunt mathematical concepts into vivid and concrete mathematical stories, and combining concrete pictures to help children understand and remember.