Our goal was to study the impact of coding on preschoolers' math abilities and to analyze their coding behaviors. Participants were six preschoolers, four years of age, from a play-based accredited program. We measured their Math abilities using TEAM and observed their coding behaviors with a structured instrument. Children used a robotic toy to engage in planned coding sessions that gradually increased in complexity. Results indicate that all children significantly grew in their Math abilities. Specifically, the children showed growth in their abilities to compare quantities, lengths, copying and finishing patterns, and building shapes. The coding behaviors of task persistence and problem solving were observed consistently, with increased metacognitive utterances in the later sessions. Implications for future studies are discussed.