Ordinal Numbers to Words Converter

Understanding Ordinal Numbers and Their Conversion to Words

What are Ordinal Numbers?

Ordinal numbers are used to indicate the position or order of items in a list. They answer the question "Which one?" in a sequence. Unlike cardinal numbers that simply count items, ordinal numbers describe the order of things.

Formula and Representation

Mathematically, ordinal numbers are represented by adding a suffix to the cardinal number:

• 1st, 2nd, 3rd for the first three numbers
• 4th, 5th, 6th, etc. for subsequent numbers

The general rule for suffixes is:

\[ \text{Suffix} = \begin{cases} \text{st} & \text{if } n \equiv 1 \pmod{10} \text{ and } n \not\equiv 11 \pmod{100} \\ \text{nd} & \text{if } n \equiv 2 \pmod{10} \text{ and } n \not\equiv 12 \pmod{100} \\ \text{rd} & \text{if } n \equiv 3 \pmod{10} \text{ and } n \not\equiv 13 \pmod{100} \\ \text{th} & \text{otherwise} \end{cases} \]

Where \(n\) is the cardinal number.

Converting Ordinal Numbers to Words

The process of converting ordinal numbers to words involves these steps:

1. Identify the cardinal number
2. Convert the cardinal number to words
3. Modify the last word to its ordinal form

Calculation Steps

Let's convert the ordinal number 23rd to words:

1. Identify cardinal number: 23
2. Convert to words: twenty-three
3. Modify last word: twenty-third

Example and Visual Representation

This diagram illustrates the conversion of the ordinal number 23rd to its word form, showing both the numeric and textual representations.