Procedural learning has dominated the study of K-12 mathematics in the United States. A lack of emphasis on the development of mathematical thinking among educators has undermined American students’ achievement in mathematics, thereby impacting students’ readiness for college and careers in the 21st century. Elementary teachers, in particular, are often under-equipped to tackle teaching practices that promote mathematical thinking and the development of conceptual mathematical knowledge, both emphasized in the Common Core Standards for Mathematical Practice. They are frequently restricted by their own content knowledge and confidence in understanding mathematics, and are themselves products of rote learning and an overemphasis on procedures.

This study was designed to support development of mathematical teaching practices among a group of upper elementary (third through fifth grade) teachers. The study utilized a qualitative action research design in order to investigate teachers’ perceptions of the development of their practice over time. Ten upper elementary teachers participated in a bi-monthly mathematics study group over a period of 6 months. The study group initially focused on using warm-up tasks to promote mathematical discourse. Data was collected in the forms of transcriptions of the study group sessions, written and verbal reflections, and pre and post-questionnaires. Throughout the study, teachers regularly experimented with practices they had rarely or never tried before. Teachers reported that the warm-ups they learned in the professional development were the driving force for changes in their mathematics teaching practices. Additionally, teachers reported that there were substantial differences in the student discourse that occurred during math time between the previous school year and this year and that facilitation of student discourse during math time became a regular part of their practice.