The document provides teaching notes for a lesson on using must and mustn't to express rules and obligations. It includes instructions for students to watch a video about growing money and check true/false statements. Students then practice using must and mustn't by identifying rules for classroom behavior and for a museum. They are asked to write their own rules for a library and swimming pool. The lesson aims to practice using must and mustn't to express rules through different classroom activities including video comprehension, matching exercises, reordering words, and writing original examples.