HaHa Bird
HaHa Bird

8 Calculator Watch Facts to Nerd Out Over

HaHa Bird
HaHa Bird

Last week, I stumbled into this very retro calculator watch from artist Nathan Bird of the wonderful site HahaBird. I don’t know why I want this watch so much. It doesn’t tell time. I don’t know how to use an abacus, and I don’t generally like things dangling from my wrist. Yet, somehow, it’s just nerdy enough that I want to clasp it to my arm and wave it in front of anyone who was ever on a math team (full disclosure: I was on the math team). Nathan’s got an instructional on his site here, if you’d like to make a similar abacus watch for yourself. But ever since seeing the post, I’ve been wanting to look up more facts about calculator watches. Here’s a little of what I found: 

1. No One Trusted Calculators


It may seem strange today, but digital calculators had to earn the public's trust. When the first Japanese pocket calculators debuted in a big way, people were so skeptical of the tiny machines' accuracy that Sharp Electronics bolted an abacus to the calculators so that users could check their work. The site Retrocalculators shows four different models that were produced up until 1985. 

2. The First Calculator Watches Were Sold At Tiffany…

Crazy Watches

The first Pulsar calculator watches debuted in 1975. They were solid gold and retailed for $3950 (nearly $18,000 in today’s money; tuition at Harvard was $3740 a year back then). But you couldn’t just pop over to a local Radio Shack to pick up a watch. According to the New York Times, the limited edition of 100 watches were only available at Tiffany, Nieman-Marcus and Marshall Field. 

3. … and Every Watch Came with a Free Pen!

Pocket Watch Show

Like an early stylus, the first editions came with a pocket pen to help those with clumsy fingers navigate the keypad. The pens also functioned to help note down answers since the early calculators didn’t have memory keys and could only read 6 digits across. 

4. The Circuit Boards Were Gorgeous

Crazy Watches

The folks at Crazy Watches took a peek inside the Pulsar 901 to reveal this beautiful circuitry (h/t Medium). The watch matches the Steve Jobs ideal of making sure that even the parts you don’t see are still aesthetically pleasing. 

5. Math for the People

It didn’t take long for the company to churn out an “economy” version. For $400 (just $2000 in today’s cash) you could pick up a steel version of the same calculator. By the early 1980s, the competition had driven down prices on cheaper models to under $20.  

6. A Watch for Closet Nerds

Casio Ad, 1985

Casio soon figured out how to add all sorts of features to the basic calculator watch. For people who didn’t want to look like the sort of people who need a calculator on their wrist at all times, Casio introduced an “invisible” feature in 1985, where users could swipe numbers and symbols across the watch face with their fingers. Answers would display in the subtle band above the standard watch face. For those who were more comfortable with their Atari-loving selves, the company added a “Space Invader Game” to complement calendar and alarm functions. 

7. It’s One Thing that Sting and Michael J. Fox Could Agree On

I don’t know what else belongs on the Venn diagram where their interests overlap, but in the 1980s, both idols sported calculator watches proudly. 

8. This Might Be the Best One

Pocket Watch Show

With 41 buttons around the watch face and all your trigonometric needs fulfilled (there are sin and cos buttons!), this Citizen Quartz watch is probably my favorite old timey calculator watch. Well, other than the abacus watch above. 

For a whole lot more on the history and evolution of calculator watches, be sure to check out this wonderful Medium story. And for a stunning gallery of Nerd Watches, be sure to poke around the Pocket Calculator Show and Crazy Watches collections. 

Live Smarter
Buying a Cast-Iron Pan Is the Easiest Way to Improve Your Cooking

You can stock your kitchen with every type of modern slicer, dicer, and immersion circulator you want, but the piece of cooking equipment that comes most highly recommended by chefs has been around for centuries: the cast-iron skillet. Like the name suggests, this essential cooking tool is molded from molten iron and coated with a protective seasoning. The result is a durable, versatile piece of cookware that’s perfect for making everything from dump cakes to sunny-side up eggs.

If you’re used to steel or aluminum frying pans, cooking with cast-iron may sound intimidating. But don’t let horror stories of skillets tarnished by dishwashers or a few hours in the sink turn you off: The metal does require some special knowledge to maintain, but what you get in return is well worth the effort. “You can cook practically anything with it,” Dominique DeVito, author of The Cast Iron Skillet Cookbook, tells Mental Floss. “It’s definitely a kitchen staple.”

So what is it exactly about cast-iron that entitles it to a spot on your stovetop? Here are some points to consider.


Iron is prized by engineers for its high-tensile strength, so you can bet it will hold up to whatever you throw at in the kitchen. But the metal does have one crucial weakness home cooks need to be aware of: water. Iron combines easily with oxygen, which is how you get iron oxide or rust. When iron is exposed to water, that liquid mixes with gases in the air to create a weak carbonic acid. The acid corrodes the iron, and the oxygen in the water bonds with the newly dissolved iron and forms iron oxide. While it won’t necessarily poison you, rust isn’t something you want flavoring your dinner.

Fortunately, keeping your skillet rust-free is easy to do. All cast-iron pans need to be seasoned before they’re ready to hit the stove. To season a pan, you can coat it with a thin layer of neutral fat like vegetable oil and heat in the oven. During the frontier days, DIY seasoning was the only option for cast-iron owners, but today most pans come pre-seasoned.

The difference between an unreliable skillet and one that’s built to last usually comes down to the quality of the seasoning. DeVito recommends cast-iron products from Lodge, which has been making cookware in the U.S. since 1896. “They put out a nice finished product that’s consistent and smooth,” she says. “It becomes something that you have an expectation about. I know that every time I go to my Lodge, it’s going to perform.”

But even well-seasoned cast-iron benefits from a little extra care from time to time. Before re-seasoning a skillet, DeVito suggests wiping it clean of any grease or caked-on food that’s left over from whatever you cooked last. Instead of scrubbing it with a soapy sponge, she washes her pan with hot water and a brush. Tough plastic works well for this, as well as chain-link metal that you can use like a hand towel to wipe down the pan. After she cleans it, DeVito likes to dry her cast-iron by placing it over low heat on her gas stovetop for a few minutes. Once it’s dry, she rubs it with a quarter teaspoon of vegetable oil using a paper towel, lets it sit over low heat for a few minutes more, and then wipes off the excess oil with another dry paper towel.

While it may not fit into your regular dishwashing routine, treating cast-iron cookware correctly pays off. A well-maintained pan is tough enough to withstand super high heat, meaning you can start cooking a dish on the stove and finish it in the oven in the same pan. The iron itself will endure any type of utensil you use on it, whether it’s a wooden spoon, metal tongs, or a plastic spatula. And if you ever damage the skillet’s seasoning or allow it to rust, it can be restored without too much trouble. “Ideally, you should be able to hand it down to your kids,” DeVito says.


Cast-iron offers health benefits beyond the nutritional value of the food it cooks. The first is a healthy dose of iron added to your meals. If you have an iron deficiency, like close to 10 million people in the U.S. do, your doctor may recommend incorporating more meat, beans, and leafy greens into your diet. In addition to eating iron-rich foods, you could also try preparing more meals in a cast-iron skillet. As the metal heats up, small amounts of iron leach out and enrich your food. The is especially apparent with acidic, higher-moisture ingredients like applesauce and tomato sauce. The iron you get is definitely not enough to replace dietary iron, but it’s a nice bonus if you’re looking for more ways to sneak the nutrient into your meals.

With cast-iron, you know the only thing being added to your food is an essential mineral. Nonstick Teflon pans, on the other hand, are made from substances that aren’t safe to be eaten. (Though you don’t really need to worry about these chemicals contaminating your food unless you’re really abusing the pan.) If your cast-iron is seasoned well enough, it will produce the same nonstick effects as Teflon without the unwanted chemicals.

And that brings us to the final health benefit: Cooking with cast-iron requires less oil than conventional pans. Because oil is already baked into the cast-iron’s exterior, you don’t have to worry about meat and vegetables getting stuck to the surface. You can either add a small amount of oil or no oil at all so you don’t end up adding more fat to your dinner than necessary.


Even without the industrial strength and bonus minerals, the cast-iron skillet would still be prized by cooks for the incredible effects it has on food. This is because of the way it reacts to heat. Iron is much thicker and denser than materials like copper and aluminum, so it takes longer to heat up. But once the metal has been heated through, it packs a lot more thermal energy than most metals heated to the same temperature. All that harnessed energy is the key to achieving crisp, golden-brown sears on foods like steak, hamburger patties, eggplant, and scallops.

And just as cast-iron takes a while to get hot, it’s also slow cooling down. That means that once you’ve left your pan to sit over a raging burner or in a screaming-hot oven for long enough, you can trust it to maintain that heat, even after filling it with cold or room-temperature ingredients. The cooling effects food has on other metals is one of the most common culprits that leaves foods pale and flabby rather than brown and crunchy.

Even when a hard sear isn’t your end goal, a cast-iron skillet is often still the best tool for the job. The versatile design makes it a great option for baking, shallow-frying, and sautéeing. A few of the items DeVito likes to cook in her cast-iron include cakes, pies, cornbread, eggs, hash browns, bacon, and vegetables. “I use it for a lot of things, like reheating leftovers and improvising with whatever I have in the fridge,” she says. “You could put a lid on it and cook rice or pasta in there—you really could put almost anything in there.”


With so many desirable qualities, you may expect a cast-iron pan to rank up there with other rite-of-passage kitchen items in terms of price. But it's actually easy to find a cast-iron pan for less than other pans that don’t perform as well or last as long. Lodge, the brand DeVito recommends, has 10-inch skillets available for around $25 on Amazon. You can find fancier cast-iron pans from brands like Le Creuset selling for over $150, but when it comes to this kitchen essential, simplicity is hard to beat.

The North Face
The North Face's New Geodesic Dome Tent Will Protect You in 60 mph Wind
The North Face
The North Face

You can find camping tents designed for easy set-up, large crowds, and sustainability, but when it comes to strength, there’s only so much abuse a foldable structure can take. Now, The North Face is pushing the limits of tent durability with a reimagined design. According to inhabitat, the Geodome 4 relies on its distinctive geodesic shape to survive wind gusts approaching hurricane strength.

Instead of the classic arching tent structure, the Geodome balloons outward like a globe. It owes its unique design to the five main poles and one equator pole that hold it in place. Packed up, the gear weighs just over 24 pounds, making it a practical option for car campers and four-season adventurers. When it’s erected, campers have floor space measuring roughly 7 feet by 7.5 feet, enough to sleep four people, and 6 feet and 9 inches of space from ground to ceiling if they want to stand. Hooks attached to the top create a system for gear storage.

While it works in mild conditions, the tent should really appeal to campers who like to trek through harsher weather. Geodesic domes are formed from interlocking triangles. A triangle’s fixed angles make it one of the strongest shapes in engineering, and when used in domes, triangles lend this strength to the overall structure. In the case of the tent, this means that the dome will maintain its form in winds reaching speeds of 60 mph. Meanwhile, the double-layered, water-resistant exterior keeps campers dry as they wait out the storm.

The Geodome 4 is set to sell for $1635 when it goes on sale in Japan this March. In the meantime, outdoorsy types in the U.S. will just have to wait until the innovative product expands to international markets.

[h/t inhabitat]


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