A descriptive, holistic, multiple-case methodology was applied to examine the nature of participation in discourse of two low- and two high-achieving grade 6 students while solving mathematical tasks in a standards-based classroom. Data collected via classroom observations and student interviews were analyzed through a multiple-cycle coding process that yielded the within-case themes of use of space, meaning-making, and peer and teacher interactions. This student-focused inquiry addressed a methodological gap in the extant empirical literature by employing video-recording as a means of eliciting student awareness and reflection, which notably revealed differences in participation between the two low-achieving students. When considering implications, the results illuminate needed additional classroom norms, issues related to relative differences in students' abilities in heterogeneous groups, benefits of using video-recording as a means of promoting student reflection, and the important role of the teacher in maintaining equitable participation.