This study explores the potential of networked handheld computers to support collaborative problem solving in small groups. Drawing on data from a middle school mathematics classroom equipped with a wireless handheld network, I argue that the sharing of mathematical objects through interactive devices broadens the "bandwidth" of classroom collaboration, expanding the range of participatory forms through which students might contribute to the work of a group and enhance their own learning. The analysis focuses on the participation strategies of those students in two focus groups who were most able to demonstrate posttest score gains from relatively low scores on a pretest. In particular, the device network provided those students with a set of collective, dynamic objects through which they supplemented and coordinated discursive forms of participation in the joint work of their respective groups.