Ordinal Numbers

Ordinal numbers are used when we want to represent an object’s rank or position in relation to other objects. For instance, 1st is the ordinal form of the number 1.
Suppose you want to list the positions of students in a class based on their test scores:
1st, 2nd, 3rd, etc.
 

To write ordinal numbers, we add suffixes to the cardinal number base. The most commonly used suffixes are -st, -nd, -rd, or th, based on the number.
It often follows the form: Ordinal Number = Cardinal Number + Suffix

For example, 2 + nd = 2nd.

• We use “-st” for numbers ending in 1 like 1st, 21st and 31st. However, this does not apply to numbers ending in 11 (e.g., 11th, 111th).

• Use ‘-nd’ for numbers ending in 2, except numbers like 12, 112, 212, etc. (e.g., 2nd, 22nd, but 12th).

• Use ‘-rd’ for numbers ending in 3 (e.g., 3rd, 23rd, 33rd)

• Use ‘-th’ for all other numbers (e.g., 4th, 5th, 6th, 11th, 12th, 13th)
   

The term ordinality refers to the position or rank of an object in a sequence. Ordinality determines the order in which something is placed in a list or sequence. For example, the order of numbers in the set {1, 2, 3, 4} is described as first, second, third, and fourth.
This should not be confused with cardinality, which refers to the size or quantity of objects in a sequence.
 

Learning about ordinal numbers from 1 to 100 can help you understand the position of different elements in a sequence. Ordinal numbers generally follow a predictable suffix pattern, especially from 1 to 20. Here’s a list of ordinal numbers from 1 to 100 :
 

Ordinal, cardinal, and nominal numbers are different numerical representations of the position, quantity, or classification of different objects. Understanding their differences will help you familiarize yourself with the concepts:

Ordinal numbers are largely utilized in representing the position, rank, or order of things. Let’s now go through a few real-life applications of ordinal numbers:

• Ordinal numbers are used to indicate the exact positions of winners in a competition. For example, 1st place, 2nd place, and 3rd place.

• We use ordinal numbers to denote dates. 
  For example, new year’s eve is celebrated on December 31st.

• The precise location, such as mentioning the specific floor where someone is, can be expressed using ordinal numbers. 
  For example, Ann is on the 4th floor.

• Ordinal numbers show which chapter a reader is on. 
  For example, the teacher is in the 6th chapter.

• We use ordinal numbers in specifying precise locations. 
  For example, we use ordinal numbers in addresses, such as: ‘Ben lives on 2nd Avenue.