Math Playground
Back to Numbers

Numbers › Cardinal/Ordinal

Cardinal, ordinal & nominal

Three jobs the same digits can do — count things, rank things, or just label things.

Cardinal

How many.

There are 3 dogs.

Ordinal

Which position.

The 3rd dog won.

Nominal

A label, not an amount.

Bus #3.

CardinalOrdinalIn words
11stfirst
22ndsecond
33rdthird
44thfourth
55thfifth
1010thtenth
2121sttwenty-first

How to spot which is which

  • If you can replace it with "some number of" → cardinal.
  • If it ranks something (1st, 2nd, 3rd) → ordinal.
  • If swapping the digit doesn't change the count or the ranking → nominal (just an ID).