The HP 12C is an excellent example of "Calm Technology"[0]:<p>1. "Communicate information without taking the user out of their environment or task". The display shows a single number: either the answer to your question or your current input. I don't need to worry about running out of battery or charging it, as I only need to once every few years. I don't need to think about my 12C except when I need to answer a finance question. I don't need to turn it off "correctly", I just turn it off.<p>2. "Gives people what they need to solve their problem, and nothing more". Basic math plus special purpose finance functions. No notifications, input history, cloud saves, Share button, upsells, political statements or otherwise claim they're making the world better, achievements or pretty but functionless UI.<p>3. "Moves easily from the periphery of our attention, to the center, and back". When I'm discussing a scenario, I don't need to sit down at a computer and design a spreadsheet. The functions in 12C are concise and operate quickly, showing the answer to one question at a time.<p>4. "Technology should amplify the best of technology and the best of humanity". 12C doesn't use ML to guess poorly what the user is trying to do, suggesting autocompletes and "are you sure" or "you mean...". It respects that the user knows what they're doing.<p>5. "Technology can communicate, but doesn’t need to speak". The display on 12C is minimal but shows everything you _need_ to know: the single number in front of you.<p>6. "Technology should work even when it fails". It either works or doesn't, no incorrect numbers reported, no missing functionality. Even when the battery dies, it will give me ample opportunity to do something about it before it actually happens, as the display dims gradually over weeks.<p>7. "The right amount of technology is the minimum needed to solve the problem".<p>8. "Technology should respect social norms". The 12C can be at the center of a conversation, and even help move a conversation forward by answering questions; I don't need to bury my face in a laptop while talking with someone, so it doesn't look like I'm ignoring them or that I've shifted my attention elsewhere; while I'm typing in numbers, it's obvious they're the numbers we're talking about. It respects the norms/customs of the field their customers work in: no need to type enter formulas for PV, FV, IRR.<p>[0]: <a href="https://calmtech.com/" rel="nofollow">https://calmtech.com/</a>