More Math Minutes is an action research study, set in a high school in the southwestern United States, designed to examine the effects of collaborative peer-group learning for low-performing Algebra I and low-performing Algebra II students. This study is grounded in Social Cognitive Theory and Constructivist Theory including Bandura’s self-efficacy theory and Vygotsky’s theory of proximal development. Participants are comprised of 20 low-performing Algebra I students as the peer-learners and 20 low-performing Algebra II students as the peer-teachers participating in a peer tutoring intervention. Quantitative and qualitative data was collected through pre- and post-self-efficacy questionnaires, pre- and post-mathematics knowledge assessments, semi-structured student interviews, photo-voice, and observations. A concurrent mixed methods design was used to analyze both types of data simultaneously. Results identified the experimental peer-teachers mathematical performance was impacted more than that of the peer-learners. Students were also more motivated to learn mathematics and to seek assistance from peers. The peer-teachers had a significant increase of self-efficacy for self-regulated learning and acknowledged learning occurred for both the peer-teachers and the peer-learners as a result of the peer instruction intervention.