This is more a historical UI query that a practical application. Nowadays it is easy to mockup a calculator that is hidden inside a classical watch. I had hoped to see this example done in some course, old demo, forum discussion, whatever in the las 40 year. But I can not remember or find any. Do you? Mandela effect welcome.

https://preview.redd.it/x8q00hmh96xf1.jpg?width=1200&format=pjpg&auto=webp&s=f407c1279babd77e9e1de02a47b0bd68301d417b