'Thousand' in the Bible

They then that received his word were baptized: and there were added unto them in that day about three thousand souls.

But many of them that heard the word believed; and the number of the men came to be about five thousand.

And not a few of them that practised magical arts brought their books together and burned them in the sight of all; and they counted the price of them, and found it fifty thousand pieces of silver.

Art thou not then the Egyptian, who before these days stirred up to sedition and led out into the wilderness the four thousand men of the Assassins?