Teaching mathematics is inherently complex, requiring a deep understanding of both the subject matter and the pedagogical strategies that foster effective learning. Effective mathematics teachers must possess a robust grasp of the mathematical content they are teaching--a proficiency often honed over years of educational and practical experience However, research indicates that gaps in this essential content knowledge can significantly impede a teacher's ability to connect classroom learning with real-world applications, thus affecting student outcomes. This phenomenological study explored how teachers conceptualize their mathematical content knowledge and how they see it influencing their ability to translate curriculum into real-world applications, thereby enhancing the relevance of mathematics for their students. The study utilized two primary data collection methods: one-on-one semi-structured interviews and researcher journaling. The interviews provided detailed participant insights while journaling facilitated researcher reflexivity. Four questions guided the research: 1. How do secondary mathematics teachers describe how they developed their mathematical content knowledge? 2. How do secondary mathematics teachers describe how they explore real-world applications and their connections to mathematics? 3. How do secondary mathematics teachers describe how the connections they made between real-world applications and mathematics content knowledge have prepared them to make math curricula relevant to students through real-world application? 4. What factors do mathematics teachers identify as key to preparing them to apply their content knowledge to real-world applications in their teaching? The findings revealed that: 1. Quality and relevant continuous learning and professional development opportunities significantly impacted teachers' ability to connect curriculum to real-world applications. 2. Integrating real-world applications improves student engagement and understanding. 3. Teachers' confidence in their mathematical content knowledge influenced their ability to effectively apply it to real-world applications, which is tied to their educational background, professional experience, and ongoing learning opportunities. 4. Collaboration among teachers, supportive mentorships, and strong professional communities were crucial for effectively applying the curriculum in a real-world context. 5. Pedagogical skills alone are insufficient; teachers also need strong mathematical content knowledge to effectively translate mathematical content into engaging, real-world relevant lessons. This study underscores the importance of comprehensive content knowledge and ongoing professional development in enhancing the practical relevance of mathematics education. [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.]