This action-based, qualitative research project involving 7 early childhood educators working in a well-established preschool child care program examined the influences of job-embedded professional development on children’s experiences of mathematics. Data was collected through observations, journals, conversations, interviews, and surveys, and then analyzed using a grounded theory model. A number of themes emerged, the strongest being those related to teachers’ increased awareness, interpretation, and support of children’s explorations in mathematics during play. This project provides an example of a successful model of teacher development for early childhood educators, and contributes to the growing field of research in mathematics education related to teacher noticing, but at the preschool level. Further, with the introduction of full day kindergarten and the emphasis on play based learning this project provides many rich examples of the mathematics present in children's every day play that can be used in future teacher development.

This action-based, qualitative research project involving 7 early childhood educators working in a well-established preschool child care program examined the influences of job-embedded professional development on children’s experiences of mathematics. Data was collected through observations, journals, conversations, interviews, and surveys, and then analyzed using a grounded theory model. A number of themes emerged, the strongest being those related to teachers’ increased awareness, interpretation, and support of children’s explorations in mathematics during play. This project provides an example of a successful model of teacher development for early childhood educators, and contributes to the growing field of research in mathematics education related to teacher noticing, but at the preschool level. Further, with the introduction of full day kindergarten and the emphasis on play based learning this project provides many rich examples of the mathematics present in children's every day play that can be used in future teacher development.