The Silver-Reed 8R, introduced in 1975 and made in Japan, is the calculator I keep on my desk for daily use (when not using my computer). It's simply designed, just the right size and its display is crisp; the only thing that sometimes throws me off is that the percentage button is placed where the equal button ought to be. But one gets used to it.
It's 120mm high by 75mm wide, and 21mm thick. It takes 2 AA batteries.
It turns on by a sliding button on the right side of the device. It has a Vacuum Fluorescent Display (VFD), a type of display still used today in places that are subjected to abuse. You'll find them in cars, microwave ovens, and some handheld video games from the seventies and beyond. The technology includes phosphor anodes which can lose their potency over the years, fading the display. Not so for this calculator, though!
A close-up of the screen.