Research indicates a problem of low mathematics achievement in schools, which not only shortchanges students’ futures, but also endangers national prosperity and security. While there is information indicating how variables impact achievement, there is lack of research concerning the impact teacher models of influence, defined as methods employed in the learning environment, have on teacher-student relationships and mathematical achievement. This sequential explanatory mixed methods design, explored teacher models of influence and their impact on the performance of algebra students at a Southeastern rural high school. Using a theoretical foundation of brain-based learning theory, the study investigated if teacher-student relationships impacted mathematical achievement and what perceptions students had of their teacher’s model of influence. Data were collected through surveys and interviews and were analyzed using an independent measures t test and evaluation of transcripts. Quantitative findings indicated that there was not a significant difference between mathematical achievement of students who perceived their teacher-student relationship as positive and students who did not have a positive perception of their teacher-student relationship. However, qualitative data suggested that a positive teacher-student relationship impacted mathematical achievement in some students. From the results, educators continue to gain understanding of the impact that teacher models of influence can have on achievement. Based on findings, the researcher recommended further investigation comparing achievement of high-risk students with varying teacher-student relationships. This study can have influence for a positive social change if teachers employ models of influence, reflecting care and concern, which may lead to an impact on student mathematical achievement.