Which of the following best describes cardinal numbers?

Cardinal numbers are defined as numbers that represent quantity, allowing us to count and indicate how many items are in a set. For example, when we say there are five apples, the term "five" serves as a cardinal number because it quantifies the total number of apples present. This fundamental characteristic is what differentiates cardinal numbers from other types, such as ordinal numbers, which indicate position or order in a sequence (like first, second, or third).

In this context, the correct choice emphasizes the core function of cardinal numbers within mathematics and everyday usage. Understanding this concept is essential in elementary education, as it lays the groundwork for students' comprehension of basic arithmetic and number theory.