Beyond cardinality: how children learn to reason about exact numbers

Abstract

Cardinality, the ability to state the quantity of a set, is an important skill in the development of precise numerical reasoning abilities. This set of studies investigates the limits of cardinal number knowledge and the additional skills needed to transition from labeling quantities to reasoning about them. Middle-income kindergarten children are found to have basic cardinal number knowledge but poor numerical reasoning ability. In addition to cardinality, they required the kindergarten educational experience to reason about exact quantities. Specifically, a more advanced understanding of cardinality, one that encompasses how parts come together to form a whole, helps a child transition from labeling to reasoning about quantities. The development of advanced cardinality is investigated and found to benefit from the use of verbal numeric labels.