Casio CA53W-1 digital calculator watch
It might have shifted from the height of hi-tech to slightly ironic over the last 20 years, but for anyone of a certain age, the Casio calculator watch will always have a place in our hearts. And you can still buy an 80s-style model in the shape of the Casio CA53W-1 digital calculator watch.
So if you need to complete any basic calculations on the move, just press the tiny buttons on your wrist and you're away. In addition to that, there's the time, date, a stopwatch, countdown, alarm and backlight, not to mention a hefty dose of 80s cool.
I had one with a space invaders game on as well - pure joy in double geography. Sadly that's not been reissued, but you can get the CA53W-1 for £22.
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