Lesson objective: Solve a real-world carpentry problem that involves multiplying non-unit fractions by whole numbers.

This lesson provides an opportunity for students to apply their knowledge and understanding of multiplying non-unit fractions by whole numbers to a real-life situation. Students are asked to figure out the sizes of wood pieces needed to construct furniture and calculate the total amount of wood needed.

Key Concept students will use:

- A multiple of \(\frac ab\) is a multiple of \(\frac1b\): (n x \(\frac ab\)) = \(\frac {n \times\ a} b\).

Skills students will use:

- multiplying non-unit fractions by a whole number
- solving addition problems involving fractions and mixed numbers (Grade 4, Unit 3)

Students engage in Mathematical Practice 1 (Make sense of problems and persevere in solving them) as they work to solve a multi-step word problem. Students add fractions to determine the length of building materials and multiply fractions by whole numbers to find the total length of wood needed. Students use this information to generate a grand total sum.

**Key vocabulary: **

- equivalent
- height
- non-unit fraction
- product
- unit fraction
- width