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Ordinal Numbers

Ordinal Numbers

Numerical words that indicate order. The ordinal numbers are: first, second, third, fourth, etc.

 

See also

Cardinal numbers

Example

Problem: Seven students finished a race. List the positions of the first five finishers using ordinal numbers.
Step 1: The student who finished the race before everyone else is in position 1st (first).
Step 2: The next finishers, in order, hold positions 2nd (second), 3rd (third), 4th (fourth), and 5th (fifth).
Step 3: Notice that ordinal numbers answer the question "what position?" rather than "how many?"
Answer: The first five positions are: 1st, 2nd, 3rd, 4th, and 5th.

Why It Matters

Ordinal numbers appear whenever you need to describe rank or position — race results, dates (January 5th), floor numbers in a building, or steps in a procedure. Understanding the difference between ordinal and cardinal numbers prevents confusion when a problem asks "which place?" versus "how many?"

Common Mistakes

Mistake: Confusing ordinal numbers with cardinal numbers.
Correction: Cardinal numbers (1, 2, 3) tell how many items there are. Ordinal numbers (1st, 2nd, 3rd) tell the position of an item in an ordered sequence. "There are 5 runners" uses a cardinal number; "She finished 5th" uses an ordinal number.

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