AT THE START OF THE FIRST FORMAL year of schooling in New South Wales, teachers gather information on a number of aspects of children's numeracy to guide their teaching program. This information is essential to planning teaching activities to meet the needs of all students. This paper reports on some key aspects of number knowledge held by 65 000 children with an average age of 5.3 years when they started in NSW public schools in 2011. The data highlights the diverse yet interconnected number knowledge children possess when they start school, and suggests directions for further enquiry.