# A Hundred Vs. One Hundred?

•  2
•  30,490
Hi! I'd like to know which is the usage difference between

1. a hundred / a thousand / a million

2. one hundred / one thousand/ one million
I'm a little confused because a vocabulary dictionary uses "a" instead of "one" while other sources use "one".

Thanks a lot for helping.
The way I see it...
When you say 'a hundred' or 'a million' you're just giving an order of magnitude, and the exact figure doesn't matter. So much so that when you say 'a million reasons not to do this' it obviously isn't important how many exactly.
When you say 'one million' or 'one thousand' then you're usually being quite precise with the figure you're giving : 'I've won a million pesos at the lottery' (lucky you even though I suspect this isn't that much) or 'This village is one thousand inhabitants'.
Sanzdifference between
1. a hundred / a thousand / a million
2. one hundred / one thousand/ one million
No difference. A hundred is one hundred. One hundred is a hundred.

Use "one" instead of "a" when working with numbers as an accountant, mathematician, or scientist might do.

CJ
Teachers: We supply a list of EFL job vacancies