Cubic Units Model
We build on Course I dimension and area models to extend student thinking into three dimensions. To get at the concepts of Surface Area and Volume, we use cubes and "cube jackets". Cube jackets are grid paper coverings that exactly cover a cube with no overlaps or gaps, and therefore serve as a model for the concept of Surface Area. The cube itself, since it occupies three-dimensional space, serves as a model for the concept of Volume. The cube is referred to as a unit cube, with dimensions of 1u x 1u x 1u.
The unit cube is the basic concept upon which geometric
measurement is built. The edges of the cube represent 1 linear unit,
and the faces each represent 1 square unit.
Here's the cube jacket for one cube. What is the surface area of the unit cube? Remember that each face of the cube is one square unit! Look at the two-cube model. What is it's surface area? What would the surface area be for a line of three, four or more cubes?
