|≈||approximately equal to|
|digits||indicates that digits repeat infinitely (e.g. 8.294 369 corresponds to 8.294 369 369 369 369 …)|
Femtogram or femtogramme is equal to 10-15 gram (unit of mass), comes from a combination of the metric prefix femto (f) with the gram (g). Plural name is femtograms.
The pound or pound-mass is a unit of mass used in the imperial, United States customary and other systems of measurement.