This action research study explored a constructivist, flipped classroom approach to teaching developmental mathematics. This study was developed in response to a concern regarding a lack of success in developmental mathematics. Throughout the study, adult developmental learners were required to watch video lectures prior to attending class. Class time was reserved for supporting and enhancing the out of class learning with collaborative in-class learning activities. The theoretical framework for the study was grounded in constructivism and supported by a community of mathematical inquiry. Data collection consisted of a beginning of semester survey, minute papers, weeks four and ten surveys, end of semester interviews, researcher journal, and faculty evaluations. The findings of the study were grouped into two sections. The first section focused on the qualitative findings and is organized into seven thematic sections. The first qualitative section discussed the student's beliefs about math, specifically their struggle and frustration with the subject. The next finding, ongoing transformations, examined the student's emerging change in perception, how they went from hating math to liking it, and the enjoyment that the adult developmental learners found in the class. The third finding focused on the shared connections the adult developmental learners were developing with each other while the fourth finding discussed the enhanced independence that the adult developmental learners were acquiring. Learning in the flipped classroom was next and noted that the video lectures gave adult developmental learners time to process mathematical ideas, allowed for flexible instruction, provided a lesson preview and became a study tool for the adult developmental learners. The sixth finding was related to the community of math inquiry theoretical framework and highlighted the collaboration with peers, dialogue and discussion, different perspectives, relaxing climate, and the challenges of group work. The final qualitative finding focused on the way that I teach including my thorough explanations, teaching presence, and the learning aids incorporated within the course. The second section of findings highlighted the quantitative findings. These findings resulted from the weeks four and ten surveys as well as the faculty evaluations. This study concludes with a discussion of the findings in relationship to the theoretical frameworks, presents implications for developmental mathematics and adult education, and includes suggestions for future research. [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://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]