Cardinal, Ordinal and Nominal Numbers

Cardinal: how many
Ordinal: position
Nominal: name

Cardinal Numbers

A Cardinal Number is a number that says how many of something there are, such as one, two, three, four, five.

A Cardinal Number answers the question "How Many?"

Example: here are five coins:

five coins

It does not have fractions or decimals, as it is only used for counting.

How to remember: "Cardinal is Counting"

Ordinal Numbers

An Ordinal Number is a number that tells the position of something in a list. 1st, 2nd, 3rd, 4th, 5th etc.

Example: In this picture the girl is 2nd:


And the two pups are 3rd and 4th.

How to remember: "Ordinal says what Order things are in".

Nominal Numbers

A Nominal Number is a number used only as a name, or to identify something (not as an actual value or position)

Examples:

  • the number on the back of a footballer ("8")
  • a postal code ("91210")
  • a model number ("380")

How to remember: "Nominal is a Name".

 

Example With Everything

cars racing

In this photo there are 6 cars. Car Number "99" (with the yellow roof) is in 1st position:

  • 6 is a Cardinal Number (it tells how many)
  • 1st is an Ordinal Number (it tells position)
  • "99" is a Nominal Number (it is basically just a name for the car)