|≈||approximately equal to|
|digits||indicates that digits repeat infinitely (e.g. 8.294 369 corresponds to 8.294 369 369 369 369 …)|
attogram or attogramme is equal to 10-18 gram (unit of mass), comes from a combination of the metric prefix atto (a) with the gram (g). Plural name is attograms.
A pennyweight (abbreviated dwt or denarius weight) is a unit of mass that is equal to 24 grains, 1⁄20 of a troy ounce, 1⁄240 of a troy pound, approximately 0.054857 avoirdupois ounce and exactly 1.55517384 grams.