This Instructional Activity is a part of the Lesson 17, Unit 1, Grade 6. This activity gives students a concrete way to review the work on volume from grade 5. It prompts students to recall that the volume of a rectangular prism can be calculated in two different ways: by counting unit cubes that can be packed into the prism, and by multiplying the edge lengths of the prism. Students also become familiar with two perfect cubes before the next activity introduces this term. As students work, monitor the different routes they take to find the volume of the built cube. They may count all of the snap cubes individually, count the number of snap cubes per layer and then multiply that by the number of layers, or simply multiply edge lengths.