Many students rely on rote algorithms that have been recently taught as they look for a direct way to tackle challenging problems. Especially for students who have not succeeded in the typical high-school curriculum, problem-solving in a novel situation is complex, and students ask for a direct way to solve rather than persevering. The purpose of this Action Research study was to investigate, understand, and strengthen some of the best practices for collaborating with teachers to increase students' success in high school math classes. Success in a high school math class is more than mastering the content objectives; students must also develop critical twenty-first-century social-emotional skills. Employers seek individuals with both content knowledge and these abilities. Specifically, in STEM job recruitment, employers prioritize social-emotional learning competencies such as teamwork, collaboration, self-regulation, critical thinking, and problem-solving capabilities. Participants and data collected in Cycle 1 were interviews with ninth-grade students, math teachers, and support educators. The Cycle 2 action steps--cocreating a math unit, implementing it in our individual classrooms, and refining the unit as we implemented it--were planned, executed, and assessed to develop best practices for teachers to work collaboratively to transform math class for their students while balancing math content objectives and practices while also providing instruction on cognitive and emotional skills. Findings included the ideas that (a) a positive class climate can promote student achievement in mathematics; (b) fostering self-regulation and learner advocacy activities can enhance math self-efficacy; (c) fostering self-regulation and learner advocacy activities can play an important role in increasing math proficiency; and (d) cocreating a course with a strong community of educators can transform challenging responsibilities into manageable pursuits with successful outcomes. [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.]