The COVID pandemic and ongoing risks to school safety drastically increased interest in full-time virtual school enrollment at the start of the decade. However, virtual schools have historically struggled to achieve mathematics outcomes comparable to their face-to-face counterparts and are at risk if they do not find ways to improve student outcomes. Unfortunately, there was limited research regarding virtual school improvement and mathematics pedagogical practices to guide virtual educators in increasing student achievement. The purpose of this study was to describe the practices, processes, and systems used by a full-time virtual school making gains in student performance on state standardized secondary mathematics tests. The qualitative case study used interviews, observations, and document reviews to describe how administrators and secondary mathematics teachers identified and supported struggling students. Data analysis through thematically coding in NVivo revealed themes of (1) designing an infrastructure to support a tiered model, (2) building capacity and autonomy, (3) continuous data evaluation and data-based problem solving, and (4) creating a culture of collaboration and communication. The findings indicated implementation of the results from previous studies on mathematics outcomes in the virtual environment, industry standards, best practices for mathematics instruction, and a multi-tiered system of supports framework to guide school improvement. The results from this study supported the findings of previous research and added descriptions of the practices, processes, and systems staff believed to support student outcomes at their school. Virtual educators and researchers could use this study to guide school improvement and future exploration. [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://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]