But, there are a few interesting mathematical scenes.

In one, we see a young Yitian studying math before an exam. Math is not his favorite nor his best subject. He dislikes that (at least from his perspective) math is made up of rules that must be memorized and not understood. His math teachers refuse to answer his questions. But, his feelings about math improve a bit when the girl upon whom he has a crush finds him studying and helps him with trigonometry.

Yitian had the misfortune to be interested in an academic career in a country where intellectuals were oppressed. He was mostly interested in studying history. Without permission from his father, Yitian's brother signed Yitian up for the university entrance exams. However, due to his own inability to read, the brother accidentally signed him up for the mathematics exam. That is why Yitian eventually became a math professor, despite his negative feelings about the subject. (Fortunately, he does begin to like it more. For example, he acknowledges while taking Real Analysis that math is not as arbitrary or non-sensical as it seemed to him in school.)

The title of the book is derived from a mathematical scene in which Yitian is trying to teach his American students about topology. He explains the idea of the genus as a topological invariant, showing them how one can transform a donut into a coffee mug (an illustration of which appears in the book) and then:

Just as it is used in that passage to convey something about his feelings for his father, math is used metaphorically to address social situations elsewhere in the book. Yitian imagines substituting people into the triangle inequality, and thinks of himself being divided into real and imaginary parts (with his real part being his body sitting in the classroom taking complex analysis and the imaginary component being connections to things from his past, like his Grandfather's stories).

Yitian only becomes a mathematician due to an error, and mathematics is only discussed explicitly a few times in this book. So, one might question whether this really is mathematical fiction or simply a story about a person who happens to be a math professor. But, it was not really a mistake by Yitian's brother which is responsible for the fact that he studied math. This is a work of fiction and that story was a decision made by the author. Why did Belinda Huijuan Tang choose to make Tang Yitian into a math professor? The fact that these mathematical metaphors recur and that the title is derived from one suggests to me that the author considers the mathematical component to be an essential, even if only small, aspect of the novel.