A disconnect exists between research that suggests that error making is a critical part of the learning process and school structures that discourage error making. This project sought to investigate and find solutions to error aversion in math classroom learning by considering the effect of classroom error culture (CEC) on learner experience. Research was conducted at a grade 7-12 independent school in the Midwest. During Cycle 1, survey, focus group and interview data around error learning beliefs and experience was collected from 172 students and 10 math faculty at the school. In Cycle 2, an action step to improve CEC by engaging faculty in a monthly professional learning community (PLC) to learn about CEC was designed, implemented, and evaluated. The faculty PLC met 6 times in a semester to learn about, plan, experiment with, and iterate on data-driven, classroom-level interventions to shift CEC. Evaluation of the action step occurred through faculty participant interviews at the end of the semester, and revealed 7 important outcomes of the action step: (a) changed faculty beliefs about the role of errors in learning, (b) a heightened awareness around and attention to error experience in the classroom, (c) increased attention to learner identity, (d) shifts in educator approach and behavior in the classroom, (e) shifts in course/assessment structure, (f) increased personal awareness around error behavior and attitudes, (g) desire for coordinated department and school effort around CEC. The study concluded that CEC has an important impact on math learning, especially for students in marginalized groups such as girls and BIPOC students, that educators have an important and multifaceted impact on CEC, and that faculty collaboration guided by student wisdom and experience can encourage and bolster action around effective error learning in math classrooms. Implications for the organization and other, similar contexts include the importance of continued attention to learners of all identities around error learning and sustained math faculty collaboration around error learning. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]