What I want to say is that the Book of Changes belongs to both cultural books and scientific books, because most of its contents are about divination and belong to scientific books, and science aims to understand the operating mechanism behind natural things.
It belongs to the cultural category, because the Book of Changes is the product of a specific culture. It adapt to that ancient times when people's science, technology and culture were underdeveloped. At that time, people generally believed in gods and thought that God was the ultimate master of all activities in nature and society. The Book of Changes is not a science and has nothing to do with it. However, as a historical document, it can help us understand the thoughts and culture of ancient people, as well as their psychology and life.
The application of the Yijing model should be reflected in many aspects. First, abstract concepts and deductive words. What was the result? Divination? Bad words? And a series of ancient Chinese characters. Second, it's auspicious. Third, the viewing device. Fourth, divination. Later, it developed into the five elements principle (fortune telling, geomantic omen, traditional Chinese medicine, etc.). Fifth, explain the origin of the universe and the cycle and replacement of everything. Sixth, Zhouyi is the origin of China's ancient philosophy. Seventh, the ancients ruled the country with the idea of performing Zhouyi.
Therefore, the classification of the Book of Changes depends on what you deeply understand. The Book of Changes is not only a master of ancient culture, but also a book about the application of early science and technology. So it can be said that it belongs to both culture and science.