'Shekels' in the Bible

My lord, hearken unto me. A piece of land worth four hundred shekels of silver, what is that betwixt me and thee? Bury therefore thy dead.

And Abraham hearkened unto Ephron. And Abraham weighed to Ephron the silver which he had named in the audience of the children of Heth, four hundred shekels of silver, current money with the merchant.

And it came to pass, as the camels had done drinking, that the man took a golden ring of half a shekel weight, and two bracelets for her hands of ten shekels weight of gold,