a/one hundred

[mimi2]

Hi,
Please tell me why I have to use "a" for "hundred" not "one"?
"A thousand is ten times more than a hundred."
Thanks.

 

[majlo]

You don't have to. You can say "a hundred" or "one hundred"; they mean the same thing.

 

[panjandrum]

You don't have to. You can say "a hundred" or "one hundred"; they mean the same thing.

That's true, but in many contexts one hundred is not idiomatic.
How far is it to Dublin?
It's one hundred miles. Correct but very odd.
It's a hundred miles.

 

[mimi2]

Thank you very much.

 

[Brioche]

Generally, "one" is used to stress the quantity or amount.

It's one hundred miles to Belfast [not 2 hundred].

Similary, "I have eaten one cake" = only one, not more than one.

 

[hamlet]

can't you omit "a" or "one" and just say "hundred"?

 

[JamesM]

can't you omit "a" or "one" and just say "hundred"?

Not in the examples given above:

"It's hundred miles to Belfast."
"A thousand is ten times more than hundred."

 

[hamlet]

and could you say "How many guys were out there?" -"hundred"? (guess not after all)

 

[Wobby]

No - you would have to say "A hundred", or something to that effect.