'Thousand' in the Bible

So then, those who had received his word were baptized; and that day there were added about three thousand souls.

But many of those who had heard the message believed; and the number of the men came to be about five thousand.

And many of those who practiced magic brought their books together and began burning them in the sight of everyone; and they counted up the price of them and found it fifty thousand pieces of silver.

Then you are not the Egyptian who some time ago stirred up a revolt and led the four thousand men of the Assassins out into the wilderness?”