Form
Spelling of Ordinal Numbers
Just add th to the cardinal number:
four - fourth
eleven - eleventh
Exceptions:
one - first
two - second
three - third
five - fifth
eight - eighth
nine - ninth
twelve - twelfth
In compound ordinal numbers, note that only the last figure is written as an ordinal number:
421st = four hundred and twenty-first
5,111th = five thousand, one hundred and eleventh
Figures
When expressed as figures, the last two letters of the written word are added to the ordinal number:
first = 1st
second = 2nd
third = 3rd
fourth = 4th
twenty-sixth = 26th
hundred and first = 1