Cash Register Used Manually Entering The Prices

Field Shops
Went Obsolete 1998
Made Obsolete By Scan-codes and RFID
Knowledge Assumed REading? price-tags
When useful Then customers were shopping. This also included actually putting price tags on all the items for sale and replacing them each time the price changed!

Still used widely by small businesses.

A UK company. 'Kwik-Save' now extinct, expected their checkout operators to know the price of all the goods for sale. The only price was above the stock in the store, nothing on the item!