The factory number is 17. If interesting mathematical riddles are integrated into mathematics teaching, it can increase the interest of the classroom, improve children's enthusiasm for learning, and let children naturally deepen their understanding of mathematics knowledge, so as to master it more firmly. There are many kinds of interesting mathematical riddles. To guess the answers to riddles, you need to know a lot of knowledge, which is helpful to expand children's knowledge. Some interesting math puzzles are thoughtful and helpful to educate children's ideology and morality, which is more acceptable to children.