At the time of my mother's childhood recollections of the early 1900s, relatively few goods came ready packaged from manufacturers. Shopkeepers weighed or measured out their goods themselves.
16 drams = 1 ounce (oz)
16 ounces (oz) = 1 pound (lb)
14 pounds = 1 stone (not abbreviated)
112 pounds = 1 hundredweight (cwt)
20 hundredweights = 1 ton
2240 pounds = 1 ton
This system of weights was known as the Imperial system.
To speed up sales shopkeepers weighed out frequently requested goods into bags while the shop was closed. There were always, though, customers who needed goods weighed out to order while they waited. Consequently waiting around and queuing to be served was a normal part of shopping. No-one seemed to mind. The women - as it was invariably women who did the shopping - knew nothing else, and it gave them the opportunity to indulge in social chit-chat without feeling guilty that they ought to be at home doing housework.
Shop-bought goods were sold by weight, volume, length, or per item, depending on what they were. Foodstuffs were generally sold by weight, measured in pounds (written as lbs) where 1 lb = 0.453592 kg. Larger units were used for heavy items like coal (which was delivered to the door), and smaller units were used for lightweight items like the powders dispensed by chemists.