This is a short lesson to review improper fractions and mixed numbers, and then to use those numbers in division problems. I used the context of making the keys of a marimba (xylophone-like instrument) to allow students to work through these problems.
The lesson includes links to videos of children playing marimbas, a warm-up, the lesson, and an exit ticket question. This can also be used as a formative assessment to help determine students' abilities with these topics.