This paper describes an iteration of a design-based research project that involved integrating commercial physical activity data (PAD) sensors, such as heart rate monitors and pedometers, as technologies that could be used in two fifth grade classrooms. By working in partnership with two participating teachers and seeking out immediate resources in the classrooms and elementary school site, we devised a set of technology-supported learning activities in which students pursued investigations related to the distances that they walk, the relationship between heights and footsteps taken, and variations in heart rates among twins and with adults. In addition, we assessed the students' knowledge before and after the PAD technology supported learning intervention using both a written assessment and interviews. Results from the written assessments indicated that the newly designed activities indeed covered the intended content related to measures of center and averages. Results from the interviews suggested that students who participated in the unit designed to incorporate PAD technologies more reliably accessed knowledge related to measures of center and averages in scenario-based problems than their counterparts who followed a traditional unit. Practical lessons related to the use of this technology with elementary school children that were learned from this design activity are also summarized. (Contains 4 figures, 1 table, and 3 footnotes.)