Lesson objective: Extend understanding of volume and develop understanding of efficiency through the application of volume formula l x w x h.

Students bring prior knowledge of volume from 5.MD.C.1-4. This prior knowledge is extended to volume formulas as students compute the volume of various solid figures. A conceptual challenge students may encounter is understanding the iteration of each layer as multiplicative.

The concept is developed through work with right rectangular prisms, which allows students to visualize all three dimensions and the iteration of each layer to fill the inside space.

This work helps students deepen their understanding of operations because students will be multiplying a series of three numbers to compute the volume while developing an understanding of the associative property of multiplication.

Students engage in Mathematical Practice 6: Attend to precision as they will specify and differentiate between units of measure (unit, square unit, cubic unit).

Students engage in Mathematical Practice 7 (look for and make use of structure) as they connect the structure to multiplicative reasoning, recognizing the iteration of layers when computing volume. Students recognize that a change in the order of numbers in a multiplication equation results in an equivalent product.

**Key vocabulary:**

- associative property
- right rectangular prism
- volume

**Special materials needed:**

- graph paper
- isometric dot paper
- unit cubes