AbstractThis paper describes an investigation of the mathematical competencies that 48 young children brought into school and their teachers’ reported planning and implementation of the mathematics curriculum for the reception year. Competence was shown in counting, recognition of numerals, representation of quantity, simple addition, subtraction and social sharing, appropriate language of measurement, position in space and on a line, and selecting criteria to sort objects. The reception teachers claimed to plan integrated topic work and stressed the importance of play, flexibility and choice, with opportunities provided for practical activities in areas where children had already demonstrated competence. The content and sequence of the curriculum was derived from infant mathematics schemes which provided a rational analysis of subject knowledge. Little account was reported to be taken by class teachers of the nature and direction of young children's developing knowledge of mathematics gained in problem‐solving situations, and little evidence of its consideration could be found in the infant mathematics schemes they used.