Accountability mandates linked to state education standards and assessments have largely replaced play in early childhood classrooms. This approach limits educators' opportunities by preventing them from using play as a means of identifying and expanding children's diverse range of competencies. In this ethnographic case study, we explore how young children living in a multilingual, new immigrant community use literacy and numeracy practices in play. Drawing from sociocultural theory and ethnomathematics, and highlighting their voices and perspectives, we show how three kindergarten-aged children draw on a broad repertoire of symbolic practices to make meaning as they work together in their play-based afterschool programme. By examining how children use literacy, numeracy and language through their play, we detail how the children collaboratively demonstrate and build knowledge as they build a castle and represent it through a blueprint. We offer implications for how teacher education can better prepare teachers to recognize the diverse range of skills and understandings children bring to school.