Professional Development SCMP May 2009

Volume of a Rectangular Prism Script

Materials needed: Snap cubes (each student needs 12)

  1. Have students draw a 3 by 4 rectangle on grid paper and find the area of the rectangle
  2. Using snap cubes, have students build a 3 by 4 by 1 rectangular prism and find the volume of the prism
  3. Have students snap their prism onto a neighbor’s prism so that their new joint prism is 3 by 4 by 2. Have them find the volume of the new prism.
  4. Have each pair snap their joint prism onto a neighboring pairs’ prism so that their new group prism is 3 by 4 by 4. Have them find the volume of their new prism.
  5. Now generalize this idea to finding the volume of any rectangular prism whose base has area A and that has height h
  6. Extend this idea to find the volume of any rectangular solid with base area A and height h.

Nets and Surface Area Script

Materials needed: Snap cubes (each student needs 24), net paper

Have students work through the following:

  1. Use snap cubes to create a rectangular prism that is 3 cubes long, 4 cubes wide and 2 cubes high.
  2. Place your prism on net paper and draw a net that could be used to re-create your prism from paper. Using a marker, draw dashed lines to show where you will fold and draw solid lines to show where you will cut.
  3. Cut out your net.
  4. Share your net with the people in your table group. Discuss similarities and differences between the nets that you and your group members created.

As students are working through the activity, notice the similarities and differences between the nets that are being created. Once they have examined the similarities and differences with the other people in their group, ask them what the net can help them find out about the rectangular prism (Answer: surface area of the prism). Then have them find the surface area of the prism.