This activity explores when children come to understand that the amount of things represented in a set are associated with a particular number word – a concept known as the “cardinal number principle”.


Presentation Type: Experiment

Age group(s): Children (4-10)

Time: 10 min

Scientific Topic(s): Psychology; Developmental Science

Supplies in Library Kit:

Additional learning resources:


This kit comes from the Living Laboratory and was developed at the Discovery Center at the Museum of Science, Boston. Click here to learn more about the Living Laboratory!

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