In China, the term "training school" or "training center" can refer to a private company that helps students, typically from 3–12 years old, improve their performance in academic subjects such as English, math, or Chinese. These schools normally operate in the evenings, on weekends, or both. Many hold classes during school recesses. Training schools can range anywhere from a one-room operation with only one teacher, to very large corporations with hundreds of thousands of students.