Wrist-Based Mathematics: Why the Casio Calculator Watch Was Peak Tech

Forget the Apple Watch. The Casio CA-53W told the world you were ready to divide a bill or launch a space shuttle at a moment’s notice.

I looked at a colleague’s wrist the other day. He was wearing a smartwatch the size of a dinner plate. He told me it tracks his sleep, monitors his heart rate variability, and allows him to answer emails while underwater. I asked him what 43 multiplied by 12 was. He panicked and reached for his phone.

Pathetic.

In 1985, I didn’t need a phone. I had the answer on my wrist. I was wearing a Casio Calculator Watch, and I was a god amongst men.

It is easy to mock it now. It looks like a prop from a low-budget sci-fi movie. But at the time, strapping a keypad to your arm wasn’t a fashion statement; it was a declaration of intellect. It was the Geek Rolex.

The Button Struggle

Let’s discuss the ergonomics, or lack thereof. The buttons on a Casio calculator watch were designed for a species with fingers the width of a sewing needle. They were microscopic rubber nubs.

If you had human-sized hands, you couldn’t just “press” a button. You had to perform a surgical strike. You needed a tool. Usually, this was the nib of a Bic biro, or a fingernail that you had filed into a dangerous point specifically for this purpose.

Trying to do a sum quickly was impossible. It was a slow, deliberate process. Press. Check screen. Curse because you hit the wrong number. Clear. Press again. But the difficulty was the point. It showed commitment to the mathematical arts.

The Language of 5318008

Of course, we didn’t use it for maths. We used it for literature.

The Casio screen was the original text message. If you typed in 0.7734 and turned your wrist upside down, it said “hELLO.” If you were feeling particularly immature (which, as a 12-year-old boy, was my permanent state), you typed 5318008. Turn it upside down: “BOOBIES.”

The hilarity this caused in a Year 8 Geography lesson cannot be overstated. We weren’t just checking the time; we were passing secret, upside-down digital notes. It was subversive. It was rude. It was brilliant.

The Exam Hall Contraband

The Casio Calculator Watch was the primary reason exam invigilators became so paranoid. Before an exam, there was the “Grand Removing of the Watches.”

“All watches with data capabilities must be placed on the desk,” the teacher would bark.

You’d unclasp the black resin strap and lay it down. It felt like handing over your weapon at the door of a saloon. Without it, you were naked. You actually had to do long division in your head? Barbaric.

But for the minor tests—the weekly spelling quiz or the mental arithmetic check—if you wore long sleeves, you were essentially a cyborg. You had an unfair advantage. You were a supercomputer in a polyester school jumper.

Indestructible Energy

We have to talk about the battery life. My colleague’s £800 smartwatch dies if he looks at it too hard. He has to charge it every night like it’s an invalid.

The Casio ran on a single CR2016 battery that contained some sort of dark magic. It lasted for five years. Maybe six. It outlasted my first car. It outlasted most of my relationships.

And the durability! The screen wasn’t Sapphire Crystal; it was plastic. It scratched if a breeze hit it. But the watch itself was a tank. You could drop it in a puddle, leave it in a PE bag for a term, or hit it with a cricket bat, and it would still be there, happily blinking “12:00” at you.

A Style Icon

The fashion world is finally catching up. You see hipsters in Shoreditch wearing them now, ironically. They wear them with rolled-up chinos and artisan beards.

But they don’t understand. They are wearing a costume. We wore the uniform. We wore the Casio because we believed in a future where technology would save us. We didn’t want a watch that told us to “Stand Up.” We wanted a watch that could calculate the volume of a cylinder.

It was ugly. It was fiddly. It was impossible to read in direct sunlight. But it was ours. And frankly, if you can’t calculate a tip on your wrist using a ballpoint pen, I don’t want to know you.