Pennyweight is derived from the price for a hundred nails in 15th century England: the larger the nail, the higher the cost per hundred. The pennyweight also bears no relation to the weight of the American "penny" (1 cent) coin, which weighs 2.5 g (for those minted after 1982). Pennyweight A pennyweight (abbreviated dwt, from denarius weight) is a unit of mass that is equal to 24 grains, of a troy ounce, of a troy pound, approximately 0.054857 avoirdupois ounce and exactly 1.55517384 grams. In the Middle Ages, a British penny's weight was literally, as well as monetarily, of an ounce
Five Grains Five Grains The Five Grains or Cereals (Chinese: , , "Wǔ Gǔ") are a grouping (or set of groupings) of five farmed crops that were all important in ancient China. Sometimes the crops themselves were regarded as sacred; other times, their cultivation was regarded as a sacred boon from a mythological or supernatural source. More generally, "wǔgǔ" can be employed in Chinese as a synecdoche referring to "all" grains or staple crops of which the end produce is of a granular nature. The identity of the five grains has varied over time, with different authors identifying different grains or even