Single Idea 17450

[catalogued under 6. Mathematics / A. Nature of Mathematics / 4. Using Numbers / e. Counting by correlation]

Full Idea

It is far from obvious that knowing what 'just as many' means requires knowing what a one-one correspondence is. The notion of a one-one correspondence is very sophisticated, and it is far from clear that five-year-olds have any grasp of it.

Gist of Idea

Understanding 'just as many' needn't involve grasping one-one correspondence

Source

Richard G. Heck (Cardinality, Counting and Equinumerosity [2000], 4)

Book Reference

-: 'Notre Dame Journal of Formal Logic' [-], p.198


A Reaction

The point is that children decide 'just as many' by counting each group and arriving at the same numeral, not by matching up. He cites psychological research by Gelman and Galistel.