'Fourscore' in the Bible

Now Barzillai was a very aged man, even fourscore years old: and he had provided the king of sustenance while he lay at Mahanaim; for he was a very great man.

I am this day fourscore years old: and can I discern between good and evil? can thy servant taste what I eat or what I drink? can I hear any more the voice of singing men and singing women? wherefore then should thy servant be yet a burden unto my lord the king?