This letter is to inform you that [Child's name] has lost [Book title] from [Class name] on [Date].
[Optional: Briefly mention what happened, e.g., "The book was left in the classroom during recess," or "It seems the book was accidentally left on the bus"].
[Optional: If you have any information about a possible location, mention it here, e.g., "We are currently searching for the book in the classroom and surrounding area."]
[Optional: If you require the book to be replaced, mention it here, e.g., "We would appreciate it if you could replace the book as soon as possible."]
Please let me know if you have any questions.
Sincerely,
[Your name]
[Your title]