Full Idea
The 'cardinal' numbers answer the question 'How many?'; the order of presentation of the objects being counted as immaterial. Def: the cardinality of a set is the number of members of the set.
Gist of Idea
Cardinal numbers answer 'how many?', with the order being irrelevant
Source
Michèle Friend (Introducing the Philosophy of Mathematics [2007], 1.5)
Book Reference
Friend,Michèle: 'Introducing the Philosophy of Mathematics' [Acumen 2007], p.14
A Reaction
If one asks whether cardinals or ordinals are logically prior (see Ideas 7524 and 8661), I am inclined to answer 'neither'. Presenting them as answers to the questions 'how many?' and 'which comes first?' is illuminating.
Related Ideas
Idea 7524 Order, not quantity, is central to defining numbers [Dedekind, by Monk]
Idea 8661 The natural numbers are primitive, and the ordinals are up one level of abstraction [Friend]