The advancement of 21st-century skills in education requires innovative teaching methods that promote critical thinking, problem-solving, and adaptability. This study explores the sustainable development of these skills in mathematics education through the application of heuristic and problem-solving techniques. By integrating these strategies, educators aim to enhance students' ability to tackle complex problems, foster a deeper understanding of mathematical concepts, and prepare them for future challenges. The research examines the effectiveness of heuristic approaches and problem-solving techniques in sustaining 21st-century competencies and identifies best practices for their implementation in the mathematics classroom. The findings suggest that these methods not only support skill development but also contribute to long-term educational outcomes by fostering a more engaging and resilient learning environment.