Construction kits—toys designed for the building or assembly of physical models—have historically played a powerful educational role in children's lives. Viewing the landscape of these kits—geometric design sets, erector sets, architectural blocks, anatomical models, chemical modeling kits, and so forth—we can see manifest strengths: at their best, they permit children to design and build three-dimensional models and to learn through tactile experience. Nonetheless, traditional construction kits also have striking limitations. They offer little in the way of direct communication with their users—for example, a traditional kit cannot offer a student information or advice about how to proceed in building a model, and as a result, crucial opportunities for student reflection may be lost. Perhaps even more importantly, traditional constructions—i.e., the models produced—tend to be aesthetically and behaviorally limited. This proposal argues that through the use of embedded computation, pieces within a construction kit may communicate with each other, with desktop machines, and with their users; and overall, by integrating construction kits with computation, the educational power and expressiveness of these kits can be greatly increased.