Correct spelling

24th

Correct spelling, explanation: this form is the correct one, because ending th is in the word form twenty-fourth. If the number ends with rd ending this is also in numeral form, for example 43rdfourty-third. This is why 24th is correct and why there is no such form as 24rd.

Definition of 24th:
numeral, ordinal number between 23rd and 25th
-What did you do on your 24th birthday? -We went to the Rabbit Hole Club.
He really can’t stay in one place. This is his 24th job in last 5 years!


Incorrect spelling

24rd

Incorrect spelling, explanation: 24rd is a mistaken form, because ordinal number twenty-fourth doesn’t end with rd but with th. Thus the correct form is 24th. rd is for those numbers which end with rd, so with third, for example 93rd. This shows why 24th is the correct form.

Incorrect spelling

24st

Incorrect spelling

Incorrect spelling

24nd

Incorrect spelling