Amazing Old Calculator (Curta) - Numberphile 

In 1964 or 1965 I was in an electrical engineering class and watched two guys sitting on the front row. Each was using a strange cylindrical calculator. It was a big class and the students using the calculators were older than the rest of us and we never found out what kind of calculators they were using. I have wondered all these years. I never again saw a calculator like that. Now finally I know. Thank You!

so does it become a grenade when you divide by zero

I want one so bad! Imagine being in a chemistry class and pulling out this bad boy in college to calculate with. Instant awesomeness status.

Now I can't help but wondering about the inner workings of this beautiful device.

No, you can do subtraction. You pull up on the handle to put it in subtraction mode. Turning the handle then decrements the turn counter and subtracts the number on the output by the number on the input. You can also do really complicated stuff like cube roots. It's a really powerful tool.

My grandfather gave me one of those - the construction is so incredible and the feel of the gears so solid. Over the years it has been difficult to explain to people exactly how amazing and great those things are.

you did not mentioned that it also can perform subtracts, divides, square roots, cubes, factors, and percentages.

it doesnt take much to realize it is indeed a magnificent little mechanical wonder.

I loved hearing the rally reference in this video! I have a friend in the rally community who has one, in fact. How were they used in rally? On a TSD rally (Time-Speed-Distance), you given distances, and the speed you are expected to go. The goal is to arrive at an undisclosed point along your route at exactly the right time. If you know how fast you are supposed to go, you can know how much time should have elapsed for each unit (10th or 100th of a mile) of distance. So the co-driver could give the Curta a crank for each "tick" of the odometer and accumulate the ideal elapsed time. By comparing that to a clock you can tell if you are running ahead (driver needs to slow a little) or behind (driver needs to speed up a little).

Just imagine if this would had been invented 2000 years ago, it would blown everybody's mind

I'm an Electronics Technician and I love collecting vintage calculators, computers, etc. This calculator (The Curta) is one of the most amazing designs I've ever seen. Thanks for the video and memories!

after an EMP strike or nuclear war this machine would still work. that's one reason why you need it. And it's just cool.

I'd love to pull that out on my next exam and see the confused looks

What tha...? that's from the fifties? i thought it was some kind of revival!. Oh boy, one of the coolest things i've ever seen.

This is soo beyond me. I cant even begin to think how someone could take mechanical parts and make a calculator like that. That man must have been some sort of genius!!!

SHUT UP AND TAKE MY MONEY!!!!

Very cool. These were of course not cheap back in the day either- a friend of mine in high school had one but I couldn't afford it. I have an Ohdner calculator of about the same vintage. It was invented in 1873 and works similarly, so the idea is an old one. But it's not a pocket device- it's the size of a small loaf of bread. The Curta is a wonder of mechanical elegance.

I was a SCCA Professional rallye driver in the early 1970s. My co-driver used a Curta to do all the time/speed/distance calculations. One of the wonderful things about the Curta is that you could, to some extent, set it up by feel (although we had interior lamps (red) for Curta, the Halda odometer, and Heuer timepieces). The Curta was tough, accurate, and easy to use - a work of art and genius.

I so want one of these now.

Anyone else want to see a Matt Parker unboxing for this?

My grandfather grew up in Germany following the second world war and stayed there until the late 80s. I'm not sure where he got it from, but he gifted me one of these and every once in a while I like to look and see how much these things cost. I'd never dream of selling it but I always thought it was interesting.

living in a digital world, i find a simple elegance in this... i wish that things like this were still made and improved upon.

I saw an ad for this in American Scientific back when I was a Jr High School. I wanted one. Had no idea it would become a cult classic!

These were very popular with land surveyors, my old boss had one, which he utterly treasured.

I loved this video and the Curta so much that I went out on eBay and bought one! Cost me $500. I hope it was worth it.

My late father bought a Curta Type II while living in Austria after WWII, and used it for many years to calculate estimated board feet while walking through his tree farms in Arkansas. I have it now and keep meaning to learn how to use it properly. It is the coolest thing I own, without question.

Really amazing! We need some company to do replicas of this engineering masterpiece.

To me, this is more impressive than any electronic device that will ever be created. It's all mechanical. It "fits" in your pocket. And it multiplies faster than my computer starts up. I'm sold.

I wish someone would make these. I would buy one.

If you do 0 to the 0, does it generate electricity?

I know this video is two years old, but I'm over here nerd-gasming. I collect antiques, especially devises that display amazing mechanical engineering like this one. I'm on the prowl for one now, thanks!

Thanks to this video, two things have happened: 1) The value of Curta calculators have skyrocketed. 2) I now have a mechanical calculator :)

A relative of mine had one, I played with it as a child and when he died they offered it to me, but I wasn't interested at the time, still kicking myself every day for that ...

I wish they would produce them again. I think that this would be an interesting way to help children learn multiplication. With turning the crank of the calculator it makes it a physical action which would probably help in memorization and it would certainly keep their attention.

amazing!. had to go into ebay and look, but the prices are a bit too high for me :-) The design of it is timeless, it looks really ace!

My best friend in the 60's-80's (sadly died in '86) was a champion rally navigator, and, indeed, had a Curta, and made special odometers, with precision gear trains, to get exact distances from a front wheel(in rear-drive cars) speedometer drive cable...even had 3 or more odometer sections for keeping track of section totals, upcoming turns, and all of that 'navigating stuff'...

Divide by zero and it becomes a hand grenade.

A friend of mine had one in the late 1960s. Truly a beautiful machine

I would be tempted to open it up. They should make a clear one

Found the manual online. For everyone wondering about division it's done the same way as multiplication, except looking for the correct output instead of the correct multiplier. So, 42/7 is calculated by setting the input to 7 and keep adding 7 to the output until 42 it reached the multiplier (white) is the answer. The manual also explains things like division with decimals, etc. And with addition, and multiplication all kinds of things are possible including square root, sine and cosine. =)

This video is going to cost me $700 cause I definitely need one of these.

I am simply blown away by the ingenuity and engineering required to build a device like that which is so user friend

That amazing object is the epitome of form and function

"Effortful" Not only does this channel provide us with amazing maths knowledge, we get an English lesson! Cheers.

That blew my mind. I want one.

I have a Curta --used it for surveying calculations in the field.

A steampunk hipster's dream

This thing honestly inspires more awe than your average 5 dollar calculator but the fact that something as complex as this calculator can be miniaturized into something as big as your thumb thanks to electronics is very much insane

Sometimes I feel digitalization has been negative to the human race when you see these analog devices.

After watching this video and Adam Savage's, I just had to had one. Managed to pick one up for a fair price and I gotta say it looks even more amazing in real life and feels great to use. No regrets (though I doubt I'll be using it for any real calculations ;))

And very soon the quantum computers shall be old dust .

Such an astounding contraption! Beautiful look, love the little noises it makes.

what happens if you exeed the maximum number it can calculate? Does it go back down to zero?

I loved the interesting bit of trivia at 4:25 about the Curta's utilization among rally drivers and their co-drivers!!! I love when the worlds of automobiles and motorsport collide with the art of science and mathematics. This kind of innovation is truly what set the automobile apart from horse-drawn carts and wagons. NOW I MUST SAVE UP FOR A CURTA CALCULATOR!!!! (Thanks, Numberphile!! Lol)

But does it run Tetris?

I believe many models of this type of calculator also had a switch to make a single turn subtract, so you could divide by clearing, adding the numerator, and then subtract the denominator until the total is less than the denominator. The value in the total display is the remainder and the value in the white count (number of turns) display is the quotient + 1 (because the initial addition added an extra turn).

Very beautiful...but looks like a granade!

I might not be the biggest math guy, but being a retro-tech man and a machinist... I have always wanted one of these since my grandfather tried to teach me math with slide rules and had me work with a telex. It's on my top 10 list of things to have in my possession by death and one of the top three to pass down to my children. Thanks for doing the light puff piece on it, it's difficult to explain the concept of a mechanical computer to newer generations with out a working example.

There was one on pawn stars

The statement is not an oxymoron. Mechanical means that it physically moves stuff with force, while digital means that it deals with discontinious numbers.

anyone has a link where i can buy like a rip off?

It looks like the kind of stuff that my grandfather would have in his house. Love you :3

I would love to have one BUT $1,600 ON AMAZON!!!!????

this is exactly the same as Marchant XLA calculator but pocket size built in 1912 ahead of Curta. On Marchant, you can do division using repetitive addition of the divisor and get accurate answer up to 8th decimal points. Also, subtraction and square root calculation is possible. Amazing!

Put 999999999 x 999999999 into it.

Before electronic calculators you could use this machine to do any arithmetic. You would only need the standard tables for the trig and logarithmic functions, which were around long before this machine was invented. The mathematicians, physicists, chemists, etc., could use calculus, statistics, etc., to derive equations, then use this machine to calculate results in the application of the equations. This was a huge leap beyond the slide rule, partly because it enabled more precise results.

What would happen if you put 999,999,999 (all 9's possible) times x (any number). I know, engineering speaking there is a limit, but what would Curta do/show? Numberphile

Truly a thing of beauty.

When he states "digital" folks he doesn't mean "electronic" LOL.Digital as in numerals.

Holly genius that man, how is even possible to imagine something like this. Amazing!

Made in Liechtenstein, I wonder what else has been made there in the 20th century. Doubt much is being made there now.

Wow, I wish these were still in production.

How do you divide using that calculator?

I'm amazed of how this things even looks :O

Display: 6 Functionality: 1 (can only do multiplication) Accuracy: 4 (no decimals) Ergonomics: 7 (fits quite snugly in the hand) Cred: 11 Durability: ???

Electricity doesn't randomly stop working after an EMP, it just frys all electronics more advanced than a vacuum tube. As for reactors, most of them have a manual physical arrest device or a chemical process that arrests the process when the reactor breaches a certain temperature. Provided that the rest of the reactor doesn't melt or break in half during the apocalyptic earthquake soon to go.

But... how do you divide numbers?

The Curta has built-in 'functions' to speed up multiplication. Also you can use tables of logs to speed up multiplication, the 13th root of 1 million etc.

The Curta crank can only be turned in one direction. Normally the counter will only count up as it is turned. If you want the counter to decrement for subtraction or division, you slide that switch. It reverses the movement of the counter.

So elegant and functional at the same time. Truly a marvel of Austrian engineering. Want. So. Badly.

Yes it is . For substraction you rotate the opposite way, and division is multiple substraction: 24/3: Insert 24 into the top register, the accumulator, (this involves zeroing it and adding 24), then set the input register to 3 and start substracting it from 24 by rotating the handle "the wrong way". When the accumulator reaches 0, read the amount of turns in the counter register. That's the result. You shift the whole thing when dividing a large number.

This is a beautiful machine and works so smoothly and elegantly.

I think I just found the world's best fidget toy ever.

You didn't mention the fact that it subtracts by adding! The way that this subtracts is so ingenious that modern computers still use the same method.

I stand corrected, in this model, to substract , you pull up the handle and rotate the right way. For the record, there were many kinds of desk calculating machines that did the same thing at that time and much earlier. This was probably the most compact one though.

Must get one. This is genius. Good work Sir Curta.

Yes, you can pull up on the handle to reveal a white (sometimes red) ring that means it is in "subtraction mode". If you then turn the handle, it will do subtraction.

I read about those in Scientific American a couple of years ago and I've been fascinated with them since. Very cool.

What's amazing is how up-to-date the design of this calculator is. It's design is so modern it looks like it could have been recently manufactured.

Square root of n, one method: Successively subtract the odd numbers from n starting with 1. Every time the odd number can be subtracted without going negative you add 1 to a counter. That will eventually give you the square root, rounded down to the nearest integer. If you want more precision just put an even number of zeros after n and move the decimal point left in the answer 1/2 of the number of zeros you put after n.

Turns out my grandpa had a mechanical calculator too. When I visited my grandma I got it of the shelve and played around a bit. At some parts it needed a bit of oil. but it is an awesome thing it could add/subtract multiply and even divide.

Ever since I read about this device in a magazine, I've always wanted to get one. Seeing it in action makes me want it even more.

Thumbnail looks like a flash grenade that freezes time in the room it explodes

It can do basic addition, you just have to change 534 to 495 during the first time you turn it round and the second time. And if you want to use decimals just change 0,7 *3,6 to 7*36 and divide by 100 in your head.

that is even more amazing than a digital calculator that can make curves and solve functions. This is grand.

Curtas are such great fun. I have a type 1 and it blows people away. Thanks for the neat little video!

What a beautiful little thing.

Mechanical machines were used to help create tables of logarithms :) These tables were used to further quicken doing roots etc.

I remember my Dad bringing one of those home from work in the 1960s.

Wow, this is an absolutely beautiful machine.