It has been argued that developing interactive learning environments that involve learners in integrating contextualized literacy experiences leads to more successful concept formation in young children. This study attempts to revisit Vygotsky’s view of the dialectical relations between culture and individual psychological functioning as mutually constitutive. By highlighting a specific literacy event, this qualitative study investigates an emergent curriculum by designing literacy-based and concept-oriented play (LBCOP) activities to foster young culturally and linguistically diverse (CLD) children’s mathematical concept formation. The paper concludes with implications of co-designing LBCOP activities by the teacher and young CLD children for both children’s concept formation and teacher design work. © 2018 Informa UK Limited, trading as Taylor & Francis Group