In this study, we investigate a program designed for young adults with intellectual disability to learn how to calculate the value of a collection of coins and notes with procedural fluency. In the first half of the paper, we establish the importance of financial literacy for people with intellectual disability and the need to address mathematical foundations using approaches that build procedural fluency. In the second half of the paper, we present findings from an analysis of pre-service teachers' weekly reflections after having just tutored a student in the program. Using educational design research, we articulate how students build procedural fluency and what supports this type of learning. This paper will be of interest to researchers and practitioners alike who are looking to apply the latest findings on effective pedagogies to the field of inclusive education.