Final answer:
The sentence that uses numbers correctly is 'Hilary said that there must have been more than 5,000 people at the stadium.'
Step-by-step explanation:
The sentence that uses numbers correctly is: Hilary said that there must have been more than 5,000 people at the stadium.
In this sentence, the number 5,000 is written as a numerical value using digits, which is the correct way to represent numbers in written English.
The other options either use the word 'five thousand' instead of the numerical value or include unnecessary punctuation marks, such as the greater than sign in the second option.
Learn more about Using numbers correctly in written English