Lesson objective: Differentiate among linear, area, and volume measurements and the units required for each.

Students bring prior knowledge of measuring area and volume from CCSS 4.MD.A.3 and 5.MD.C5. This prior knowledge is extended to include length, area, and volume all in the same context as students identify different measures of a geometric solid. A conceptual challenge students may encounter is confusing the units needed for each type of measurement, particularly since linear, area, and volume units will all be applied to the same rectangular prism in this task.

The concept is developed through work with a prism and a list of unlabeled measures, which require students to use their understanding of geometry and measurement to determine what each measure represents.

This work helps students deepen their understanding of number because one of the key differences among length, area, and volume are the units used to express those measures.

Students engage in Mathematical Practice 6 (Attend to Precision) as they carefully examine the figure and use what they know about measurement and geometry to determine which number represents which measure; students recognize that measurements without units hinder the understanding of those measurements.

**Key vocabulary:**

- area
- cubic units
- edge length
- one-dimensional
- plane
- square units
- three-dimensional
- two-dimensional
- units
- volume

**Special materials needed:**