I first came in contact with electronic calculators at university, in about 1970. A huge thing from TI with Nixie tubes, so expensive that we only had one and had to share it. Only a few years later I got an HP 45, much smaller but also very expensive. Times have changed. A week or two ago I bought a small basic pocket calculator on eBay for $2.97, including postage. The days of expensive electronics are mainly gone. It arrived today, and it does the job (calculations in the kitchen). It even has sound for the key presses. But the documentation! The only documentation of any kind was on the box:
Those aren't even instructions, just examples. But who needs instructions? Everybody know how to use a pocket calculator.