This action research study explores the interplay between language acquisition and high school mathematics education, particularly for multilingual learners. The study challenges conventional, segregated approaches to math and language learning that emphasize formulaic memorization and algorithmic methods, contributing to the "math person" fallacy and often marginalizing students. Guided by the disciplines of second language acquisition theory and learning experience design, the research investigates how tailoring mathematical activities to facilitate language acquisition enhances both instructional outcomes and student engagement. The study's primary research questions probe the mutual empowerment of language and mathematics learning, focusing on their impact on adolescent learners. The findings underscore that elements such as learning culture, ethics, and pedagogy are intricately linked and that language-responsive teaching strategies share significant commonalities with engaging math education practices. These insights inform educators' instructional decisions, offering activities that bolster social and academic language alongside mathematical competencies. [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.]