As already stated, either would do here in the US.
But seeing as you mention million, billion, etc., here is a difference:
In the US, we would call ten million dollars (or tiddlywinks, whatever) "ten million". I have noticed a British to refer to it as 'millions' and so the quote would be "ten millions". In the US, the multiple is already implied once one has gone beyond two (or apparently, the third floor of a UK dwelling, assuming a building with a 'first floor' is a single story place).
And by the way, as you call a rental apartment a 'flat', does that distinguish it from something else? Do Brits. live in round places sometimes? Bent places? Not sure why the word "flat" as a name for a rented dwelling space. ?? Were most of them crooked in the olden' days?
Brian
numbers
7600
is this seventy six hundred or seven thousand six hundred ?
what about 7633?
Also our billion has been devalued. It used to be a million million but more recently we have adopted the US convention of a thousand million. Same goes for a trillion which used to be a million million million