Thousands in English

In English, when we write numerals or digits, we separate thousands with a comma (,) as in this example: 5,300,000

We count 3 digits from the right and insert a comma, like this:

1,000 one thousand
4,500 four thousand, five hundred
96,000 ninety-six thousand
450,000 four hundred and fifty thousand
$6,300,000 six million, three hundred thousand dollars

When we have exact numbers with thousands (and hundreds), we do NOT add "s".

So, for example, for 2,500 we write and say:
two thousand, five hundred

We do NOT write and say:
two thousands, five hundreds

But note that we DO add "s" when we don't have an exact number:
There were thousands of people at the game.
Hundreds of people complained on Twitter.
Thanks to: Gabriel
Be careful with commas and points. Some languages use them in the opposite way!