Definition
Pound
A pound is a customary unit of mass equal to 16 ounces.
What it means
Pounds are useful for masses that would take many ounces to describe. The unit stays the same size, so a mass written as 4 lb can be compared with another mass written in pounds.
Remember it
Bundle 16 one-ounce pieces together: that bundle has a mass of 1 pound.
Example
A parcel has a mass of 5 pounds. Because each pound is 16 ounces, its mass is 5 × 16 = 80 ounces.
Watch for
This card owns the mass unit. It does not mean pound sterling, the unit of money, or pound-force, a unit of force.
Common mix-up
Everyday speech often says an object “weighs” so many pounds; mathematically, this card is about the pound as a mass unit.
Exact meaning
In the avoirdupois system, one pound (lb) is a unit of mass equal to 16 ounces and exactly 0.45359237 kilograms.