This problem, along with the rest of the problems in the Proof for All (st)ages feature, provides an excellent context for observing, conjecturing and thinking about proof, and for appreciating the power of algebra.
Possible support
Encourage students to work in pairs and make use of the hints available in the Getting Started section.
Possible extension
Students could be encouraged to work on the rest of the problems in the Proof for All (st)ages feature.