The Early Years Learning Framework for Australia governs early childhood education in the years before school in Australia. Since this framework is not a curriculum, early childhood educators report uncertainty regarding what mathematical concepts to teach and how to teach them. This implementation study, positioned within the broader E4Kids study, explored the enactment of a suite of play-based mathematics activities by five early childhood educators in different settings over a seven-month period. The educators' approaches to incorporating the activities are discussed in light of the reported implementation frequency and the duration of activities. A regression analysis predicted significant changes in children's Fluid Intelligence/Reasoning associated with attending high-implementation programmes. Recommendations are made for further investigation of the enactment of mathematics activities in early childhood settings and for the provision of professional learning opportunities that focus on supporting children's concept development as well as their mathematical skills.