THE MYSTERY OF THE STOLEN BEANS. This resource is a complete Year 5/6 Maths lesson that teaches and reinforces prime numbers through an engaging mystery-solving activity. Inspired by the book Bean Thirteen by Matthew McElligott, pupils become detectives, solving a series of prime number clues to uncover the Mystery of the Stolen Beans! The lesson can be delivered without the book, but using Bean Thirteen beforehand provides a fun and memorable introduction to the concept. The resource is an original teaching activity and is not affiliated with or endorsed by the author or publisher of Bean Thirteen. Designed for Upper Key Stage 2, this 1-hour, ready-to-teach lesson encourages mathematical reasoning, problem-solving and collaboration while keeping children motivated and engaged. This resource includes: Editable Microsoft PowerPoint lesson Editable Microsoft Word lesson plan Printable, editable Microsoft Word pupil resources Editable Microsoft Word answer sheets Perfect for Year 5 and 6 teachers looking for a fun, low-prep lesson to introduce or consolidate prime numbers.