教科書

1. Origins, structure, and basic meaning

• Structure: 教科書 is read as きょうかしょ and means “textbook”.
• Basic usage: The examples show a textbook opened before class and an old mathematics textbook from an older brother.

2. Common pitfalls and similar expressions

• Distinguishing senses and uses
  • It is the standard book organizing a school subject’s curriculum, unlike supplementary 参考書 used mainly for reference or study support.