Mathematical aptitude in the United States has been a concern over the past few decades, not only from an international perspective but from a student proficiency perspective. This phenomenon is also further negatively impacted due to COVID-19 associated learning loss. Correspondingly, there are calls for students to develop entrepreneurial skills to thrive in the 21stcentury economy. The purpose of this quasi-experimental study was to examine whether participation in an entrepreneurship class was related to mathematical proficiency (Algebra II) in high school. Data on students from two school districts were used, consisting of 2,741 and 1,172 Algebra II students in each school district, respectively. The data on each school district were disaggregated as each school district provided a differing dependent variable. School District One provided standardized assessment data from a state assessment in Algebra II as the dependent variable, while School District Two was only able to provide Algebra II grades instead. Data on student, classroom, and school characteristics were collected for this analysis. Multiple regression analyses and propensity score matching were used to explain relationships between individual variables and math proficiency in Algebra II. Conclusions from this study add to the existing literature surrounding math proficiency and contextualized learning. The average treatment effect (ATE) was significant for School District One, indicating that had Algebra II students taken entrepreneurship, their Algebra II post-test score was estimated to increase by 13-15 points. The average treatment effect on the treated (ATET) was not significant, indicating that students who actually took an entrepreneurship course did not see gains due to this course enrollment. However, the ATE significance depicts the positive relationship that entrepreneurship could have on the math outcomes of students who do not typically enroll in classes such as entrepreneurship. Numerous variables were evaluated to determine individual relationships, of which the following were significant with relation to Algebra II: the Algebra I post-test score, Asian race variable, number of Advanced Placement (AP) and/or honors classes taken, math teacher years of experience, teacher staffing ratio within the school, entrepreneurship class enrollment, free and reduced lunch variable, Algebra I grade, and the gender variable. [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.]