In the previous sections, you looked at student representations of problems that deal with spatial visualization; explored using graphic representations to help develop the concept of variables; and studied the application of representations in the middle-grades classroom.

Now that you are familiar with the standard and some of its aspects, you can see how one teacher applies it. Middle school teacher Michelle Mullin wants to evaluate how well students in her seventh- and eighth-grade math class understand how to calculate the surface area of a "raft" of n rods, where n can be 1 through 10.

How does representation fit into this picture? First, consider a problem similar to the one Ms. Mullin sets for her students.

  Apply what you've learned