It is widely understood that preschool should provide children the mathematical foundational skills necessary for later success. This study examines seven preschool teachers and their use of a variety of pedagogical strategies to develop foundational mathematics concepts. Using a qualitative research design, this study uses the CLassroom Assessment. Scoring System (CLASS) observation tool to examine how preschool teachers use instructional learning formats, concept development, language modeling, and quality of feedback to support mathematical learning. Following analysis using the CLASS, data were reexamined for use of messing about strategies. Results indicate that preschool teachers use a variety of formats for teaching mathematics but develop concepts using feedback and language less frequently. While teachers do allow children to mess about with mathematical items, they do not use this time to extend thinking. (author abstract)