AbstractThere is growing interest in mathematics learning progressions in early childhood education. Counting is a skill usually developed early in life. The application of the counting principles in early childhood typically entails counting objects. This poses challenges for learning about zero. Indeed, the word “zero” is seldom used in the context of early childhood education. Early childhood educators could purposefully introduce children to zero as a concept and facilitate children’s understanding that zero is a number and more than just the absence of something. “Zero” is introduced in school, but little guidance is provided to teachers within the Australian Curriculum for Mathematics in the Foundation year. This study contributes to a small corpus of research that has investigated preschool children’s understanding of the concept of zero. Unlike other studies, the method employed to elicit children’s knowledge was informal and more similar to educator-child conversations that occur within a playbased curriculum and contribute to formative assessment. Data are presented from 20 children, aged from three to five years, participating in a regional early learning centre. Six children demonstrated familiarity with the symbol for zero (“0”) and/or the concept that zero describes a numerical quantity. Asking a follow-up question encouraged children to share their thinking. The importance of early childhood educators purposefully supporting children’s familiarity with the word zero along as well as the concept of zero is proposed.