The National Science Foundation (NSF) awarded a $430,572 Project Grant under the STEM Education (CFDA 47.076) program to the University of Georgia Research Foundation, Inc. (UGA Research Foundation). The project aims to investigate how to meaningfully incorporate "playful elements" into the teaching of foundational undergraduate and secondary mathematics topics, such as algebra and calculus. The research will examine the effects of incorporating characteristics of mathematical play, such as exploration, self-selection of goals, and enjoyment, on students' mathematical reasoning and learning. The project will implement a multi-phase design experiment model, leveraging clinical interviews, small-scale teaching experiments, and whole-class teaching experiments to generate findings on the aspects of task design, instruction, and classroom interactions that support mathematical play and its benefits for adolescent and undergraduate students. This award reflects NSF's priority of supporting fundamental STEM education research that generates knowledge in critical areas such as STEM learning environments and student engagement.