Before using the isometric drawing tool, it would be helpful to review volume and surface area of three dimensional figures, namely ones built from cubes. In pairs, students should discuss their own definitions and give examples of the uses of each. Students can share their definitions and examples with the class. Students may state the following:
The volume of a solid is the number of unit cubes that fit inside. For example, if students were packing a box, they might say that the volume is the number of individual cubes that will fit inside the box.
The surface area of a solid is the number of square faces that show on the outside. For example, if students were wrapping a box, they might say that the surface area is the amount of wrapping paper needed to cover the box.
Have students open the Isometric Drawing Tool. Using the tool, they should build the following figure:
This figure, along with the others from this lesson, is available for you to download from the following PDF and make into an overhead transparency:
Tell students to determine the volume and surface area of this figure. Students can simply count the number of cubes to determine the volume. To determine the surface area, the students can use the Separate Faces feature (by clicking on the "Explode" button) 
to separate the cubes into individually faces (by clicking on the faces)and count the number of faces. They should determine that the surface area is 18 square units.
Students should create each of the following figures and determine the surface area and volume of each.
In pairs, students can compare their solutions and note any observations. Ask students, "What conjectures or statements can you make about the surface area of a figure built using 7 cubes?"
Students should create the following table in their notes:
|
# of
cubes
|
Volume(s)
|
Surface Area(s)
|
| One
|
| |
| Two
|
| |
| Three
|
| |
| Four
|
| |
| Five
|
| |
| Six
|
| |
The first column lists a number of cubes you should use to build a figure (one to six).
In the second column, list the possible volume(s) of a solid built with that number of cubes.
In the third column, list the possible surface area(s) of a solid built with that number of cubes.
In pairs, students should build the specified figures and find all of the possible volumes and surface areas for each figure. Students can answer the following questions with their partners.
