The overall aim of this study is to enhance mathematics learning experiences of 10-14-year-old students in Ireland, with a specific emphasis on promoting productive dispositions in mathematics. A productive disposition is a core element in the development of mathematical proficiency. However, how students develop a productive disposition in mathematics has received little attention in the research literature. The study addresses this gap in research and practice, placing productive disposition as a core element of mathematical proficiency. To achieve this, the study employs the use of rich tasks as a tool to enhance mathematics learning experiences and productive dispositions of 10-14-year olds in Ireland. This study is primarily qualitative in nature, and an 'Educational Design Research' (EDR) is adopted as the overall research approach. This study adds to the relatively few empirical studies conducted on students' productive dispositions in mathematics. The findings of this study favour the role of rich mathematical tasks in developing students' productive dispositions in mathematics. The findings indicate that the rich mathematical tasks based on the design principles developed in this study afforded opportunities to develop mathematical thinking, fostered positive student attitudes, and enhanced confidence in mathematics. This study offers valuable insights into students' perceptions of mathematics learning during a critical developmental period (ages 10-14). The findings have implications for designing and implementing rich tasks in mathematics that can support student learning and foster productive dispositions in mathematics.