Cardinality is the counting and quantity principle referring to the understanding that the last number used to count a group of objects represents how many are in the...

Abstraction is the counting and quantity principle referring to the understanding that we can count any collection of objects, whether tangible or not. For example, the...

Conservation is the counting and quantity principle referring to the understanding that the count for a set group of objects stays the same no matter whether they are...

Students have an understanding of order irrelevance when they are able to count a group of items starting from different places.

This “stable list” must be at least as long as the number of items to be counted. If counting 20 items, their stable list of numbers must be to at least 20.