Ordinal Numbers

An ordinal number tells the order of things and helps in representing an object’s rank or position in relation to other objects. The order can be based on size, preference, time, importance, or any sequence that compares objects. For example, the rank of students in a class can be described as 1st, 2nd, and 3rd. These are ordinal numbers because they describe positions. 

Ordinal Numbers Definition
 

Ordinal numbers are numbers that indicate the position, order, or rank of objects or people in a list or sequence. They show where something stands rather than how many there are. Examples include 1st, 2nd, 3rd, 4th, and so on.

What is Ordinality?
 

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 the numbers in the set {1, 2, 3, 4} is first, second, third, and fourth.
Do not confuse this with cardinality, which indicates the size or quantity of objects in a sequence.

To write ordinal numbers, add the appropriate suffix to the base cardinal number . 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, such as 1st, 21st, and 31st. However, this does not apply to numbers ending in 11.

• Use ‘-nd’ for numbers ending with 2, except for numbers like 12, 112, 212, etc.

• 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)
   

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 :
 

Numbers can be used not only to count objects, but also to show their position in a sequence. To differentiate these purposes, two types of numbers are used in mathematics, namely, ordinal numbers and cardinal numbers. While cardinal numbers tell us how many objects there are, ordinal numbers tell us which position an object holds in an ordered list. The following table shows the significant differences between cardinal and ordinal numbers. 

Ordinal numbers and nominal numbers are two distinct concepts used to identify objects and show their position in an ordered group. The following table shows the differences between ordinal and nominal numbers.  

Given below are some tips and tricks to easily remember and learn ordinal numbers. 

• The suffix pattern always have exceptions. While most ordinal numbers take -st, -nd, -rd or -th depending on the ending digit like 1st, 2nd, 3rd and so on, there are exceptions like 11th, 12th, 13th, where, always -th is used even if they end in 1, 2, 3, and so on.
   
• Instead of just looking at the final digit, sometimes look at the last 2 digits to decide the suffix. For example, 112th and 12th. 
   
• To learn easily, make flash cards for numbers like 11, 12, 13, 21, 22, 23, 101, 111, etc. 
   
• Say out loud while learning. Speaking helps stick up the correct suffix in your mind.  
   
• Practice with real examples like applying ordinal numbers to dates, floor buildings, ranks, etc. for example, 31st December, 4th floor and 3rd rank. 
   
• Use fun real-world activities, like lining up toys or students and asking who is 1st or who is 2nd? This makes learning more practical and enjoyable. 
   
• Parents and teachers can intentionally incorporate ordinal numbers in daily routine or conversations like “your seat is in the 2nd row”, or “bring the book from the 3rd row of the shelf”, to help students learn ordinal numbers naturally. 
   
• Use visual tools like posters, number lines, medals, or objects placed to help students visually learn the concept of ordinal numbers.
   
• Encourage students to use ordinal forms when stating dates, such as “today is the 5th of March” or “tomorrow is the 2nd Saturday of the month”.
   
• Parents and teachers can use technology and interactive online tools, such as quiz pages, ordinal-number worksheets, or online games, to make the learning process more engaging and playful.

Ordinal numbers are largely utilized in representing the position, rank, or order of things. Here are a few real-life applications of ordinal numbers:

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

• Dates: We use ordinal numbers to denote dates. For example, New Year's Eve is celebrated on December 31st.

• Floors in buildings: 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."

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

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