The purpose of this research was to investigate students' mathematical understandings of fraction division with an ethnomathematics/STEM framework. A small group teaching study (Cobb et al., 2003) was conducted using design research methodology to examine how students interacted with the curriculum. The researcher served as interventionist and collaborated with a sixth-grade classroom teacher and seven students after school over a two-week period in South Los Angeles. Data collection included pre and post interviews with students, a researcher reflection log, a notebook that students developed, and both audio and visual recordings. The data were analyzed using an interpretive framework with a social constructivist approach (Burr, 2015; Cobb et al., 2003). The results indicated that students developed an understanding of math concepts for fraction division: the more a whole is divided, the more pieces you have, and the smaller those pieces are; and that there is a proportional relationship between speed and time, relative to the concept of distance equals the product of the rate and time. Students struggled productively with developing visual representations of the fraction division they were doing, and were challenged with new parameters used for estimating, as well as with understanding their calculations. However, the students perceived both cultural contexts and ethnomodeling to have supported their understandings of fraction division within the context of the ethnomathematics/STEM framework. This teaching study was the first iteration of a larger design study, and thus the reflection and findings from this initial iteration will support the preparation for engineering the advancements necessary for the next iteration in the future. [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.]