Glossary math Term Page

Cardinality

The size of a set in terms of how many elements it has

cardinality #math#set-theory

Aliases

cardinalityset size

Prerequisites

Mathematical set Function (math)

Related Concepts

Mathematical set Function (math)Bijection

Core Idea

Cardinality describes the size of a set. For finite sets, this matches ordinary counting. For infinite sets, it is compared through bijections.

Role In This Blog

In Mathbong, cardinality is where set theory starts to explain why infinite collections can still be compared in a precise way.

Posts Mentioning This Concept

[Set Theory Series 8] Cardinality and the Basics of Infinity Start from the size of finite sets and build the first intuition for comparing infinite sets through bijections.[집합론 시리즈 8편] 집합의 크기와 무한의 기초 원소 수로 보는 집합의 크기에서 출발해 유한집합, 무한집합, 가산의 기초 감각을 소개합니다.[Set Theory Series 10] Set Theory Review Review the core ideas and symbols from the set theory series and prepare to move on to deeper topics in discrete mathematics.