Lesson 6

The purpose of this lesson is for students to use their understanding of the structure of rectangular prisms to find volume and write numerical expressions to represent volume.

In a previous lesson students learned to find the volume of a rectangular prism by multiplying the number of cubes in a base layer by the number of layers. They connected this understanding to multiplication of length, width and height to find volume. They also used a two-dimensional representation of a base and its corresponding height to find the volume of a rectangular prism.

In this lesson students write and interpret numerical expressions that represent the volume of rectangular prisms. Students use what they know about rectangular prisms to reason whether or not an expression represents its volume.

During the next lesson, students will describe which standard cubic unit they would use to measure the volume of objects that are shaped like rectangular prisms. Consider which objects students see on a regular basis in their communities that are shaped like rectangular prisms and bring picture of those objects to show students during the next lesson. If possible, consider going on a prism scavenger hunt around the community before the next lesson.

Math Community

Tell students they will reflect on their identified norms at the end of this lesson.

• Create a set of cards from the blackline master for each group of 2.
• Have connecting cubes available for students who need them.

As students matched expressions to images of prisms today,  what evidence did you see that they are building on their understanding of the structure of rectangular prisms?