'Shekels' in the Bible

When he cut the hair of his head (now it was at every year's end that he cut it; because it was heavy on him, therefore he cut it); he weighed the hair of his head at two hundred shekels, after the king's weight.

and Ishbibenob, who was of the sons of the giant, the weight of whose spear was three hundred [shekels] of brass in weight, he being armed with a new [sword], thought to have slain David.

The king said to Araunah, "No; but I will most certainly buy it from you for a price. I will not offer burnt offerings to Yahweh my God which cost me nothing." So David bought the threshing floor and the oxen for fifty shekels of silver.