He had taught at the same cram school for seven years now, and he was popular with the students because he knew how to convey the subject succinctly and clearly, and he could answer any question on the spot. Tengo surprised himself with his own eloquence. His explanations were clever, his voice carried well, and he could excite the class with a good joke. He had always thought of himself as a poor speaker, and even now he could be at a loss for words when confronted face-to-face. In a small group, he was strictly a listener. In front of a large class, however, his head would clear, and he could speak at length with ease. His own teaching experience gave him renewed awareness of the inscrutability of human beings.

Tengo was not dissatisfied with his salary. It was by no means high, but the school paid in accordance with ability. The students were asked to do course evaluations periodically, and compensation hinged on the results. The school was afraid of having its best teachers lured away (and, in fact, Tengo had been headhunted several times). This never happened at ordinary schools. There, salary was set by seniority, teachers’ private lives were subject to the supervision of administrators, and ability and popularity counted for nothing. Tengo actually enjoyed teaching at the cram school. Most of the students went there with the explicit purpose of preparing for the college entrance exams, and they attended his lectures enthusiastically. Teachers had only one duty: to teach their classes. This was exactly what Tengo wanted. He never had to deal with student misbehavior or infractions of school rules. All he had to do was show up in the classroom and teach students how to solve mathematical problems. And the manipulation of pure abstractions using numerical tools came naturally to Tengo.

When he was home, Tengo usually wrote from first thing in the morning until the approach of evening. All he needed to satisfy him was his Mont Blanc pen, his blue ink, and standard manuscript sheets, each page lined with four hundred empty squares ready to accept four hundred characters.