1. He took an A-level Math Test.
2. Through a color of a car. A good day is when he sees four red cars in a row on the way to school, and a bad day is when he sees four yellow cars in a row.
3. Screaming when angry and not smiling.
4. The problem is the underground system is confusing and noisy, which causes him to feel sick. He sits on a bench near the train track for five hours trying to cope with sounds of the trains, the crush of people, and his fear of trying something new.