Amazing Old Calculator (Curta) - Numberphile

Alex's book: amzn.to/1l0yX46
The Curta is a pocket-sized, mechanical, digital calculator!!! It was invented by Curt Herzstark.
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Shown here by Alex Bellos, author of Alex's Adventures in Numberland.
More about our contributors, including Alex, at www.numberphile.com/team/index...
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[@jimbagley5387]

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!

[@karthiksriram4632]

Oh nice... How old are you now? 😊

[@flix7280]

@Boco Corwin now 4 years

[@Krektonix]

@flix7280 now 5 years

[@l4wl3rbl4d3r]

so does it become a grenade when you divide by zero

[@yousorooo]

l4wl3rbl4d3r You can only add with this device.

[@christianchoi1]

Derek Leung wrong you can subtract as well they didn't add that in or they didn't know. You pull the thing you circle around up and it will do subtraction

[@yousorooo]

*****​ Go learn how this device actually works please. The mechanism inside can only do addition, just like an ALU used by modern computers.

[@yousorooo]

*****​ Go learn how this device actually works please. The mechanism inside can only do addition, just like an ALU used by modern computers.

[@428yt4]

Derek Leung lol double post

[@eyesofphysics97]

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.

[@ghuegel]

People who think that a Curta calculator equals "awesomeness" are the kind of people I love the most.

[@eyesofphysics97]

ghuegel Like, the definition of a nerdgasm.

[@jyk000]

Pulled one of these babies out in my SAT 2 Math test as a joke, but the proctor got mad at me. Proctor for my IBHL Math Exam didn't mind though.

[@eyesofphysics97]

jyk000 Really? You have one of these?

[@jyk000]

Bought on eBay when this first came out for 500 bucks. Type 2

[@BGroothedde]

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

[@theworldslasthope]

type in how the curta works into the search bar, amazing 3d video

[@BGroothedde]

Golden Mean Media I know, i shared that video in this commentsection as well. A beautiful video indeed! ^^

[@theworldslasthope]

Bas Groothedde Aah. Its only because I had watched that video just before this one I thought it might be of great help to you. I'd say I understood about 75% of it when I watched it. :)

[@BGroothedde]

Golden Mean Media I had to re-watch it as well, what a simple yet complicated machine!

[@brettefantomet]

+Bas Groothedde there is a vid about it on youtube... sorry for bumbing a year old post

[@MrDylansYT]

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.

[@wipi-dn2jf]

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

[@koubun02]

It CAN??????

[@Nothing_serious]

wipi 8055 Can it even make a decimal number for square root?

[@flashpeter625]

Technically, it can only add. But with help of moving the decimal point and similar tricks, you can do all of those operations. Algorithmically, it is very similar to what the arithmetic logic unit in every electronic computer does.

[@davecrupel2817]

That....is disgustingly incredible....what a marvel of engineering!

[@HeineArthur]

By pulling the lever, the Curta calculator goes in subtraction mode by reversing gears. It can do it mechanically, not with operation tricks.

[@sasjadevries]

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.

[@zollen123]

Good thinking.

[@saraha180]

I agree that it's cool, but you don't really need a machine to do arithmetic multiplication. You can do it with a pencil and paper, or even just a bit of charcoal and a wall. As far as practical devices for doing science or engineering, a slide rule is *way* more powerful.

[@sasjadevries]

Sarah with pen and paper you can make mistakes and it would take more time when you have 8 digit numbers or so. And the thing is if such a caltulator would become more popular people will start improving it and more functions would be added.

[@micheals1992]

Wouldn't it fry its cogs?!

[@etomicbomb1753]

I have a calculator that was invented in the 1600s. I think I am also set for the EMP strike/ nuclear world war. YEAH!!!!

[@autodidactusplaysjrpgs7614]

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

[@alfredomoreno8516]

hahahaha LOL

[@TartsFlying]

+Alfredo Moreno great input there hahahaha LOL

[@azmah1999]

And then you'll have to calculate sin(π/7) and you'll be screwed. ^^ But I admit that it would be amazing

[@danijel124]

grenade!!!! everybody on the floor ;)

[@Peter_1986]

+Anim' Max by Mojert If I am expected to use a calculator during an exam and I have forgotten to bring it then I just leave those uncalculated parts in symbolic form. =P It's the solution steps that are important anyway, and I can always show those steps without making numerical calculations, since variables have nothing to do with specific numbers.

[@Nekotamer]

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

[@martiddy]

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

[@carterwood4197]

Some genius 2000 years ago may have been able to design something like this, but there's no way they could have built it back then. The engineering is too advanced. They'd need a way to make steel into extremely precise gears and all that for this to work. So yeah, minds would be blown. They'd probably all cry witchcraft.

[@TonboIV]

@@carterwood4197 Yeah, precision is a technology of its own. This device can only be made in the industrialized world.

[@Bronze_Age_Sea_Person]

Ancient Greeks made the antiktera mechanism,which is quite the complicated machine,it's not far-fetched to think that a "Greek Curt" could be out there.

[@TonboIV]

@@Bronze_Age_Sea_Person The components of the Anitkthera are much larger, and also somewhat simpler. It's a very surprising device to be sure, but it doesn't measure up to modern precision engineering.

[@Kamadev888]

They did, friend, and even more complex- the Anthikithera device.

[@JBLewis]

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).

[@adamplace1414]

My dad used to lay out and participate in those rallies, and he had a Curta. Since he's passed, it's now my brother's, and one of his most prized possessions.

[@JBLewis]

@@adamplace1414 Love seeing that this video is getting fresh views after the Objectivity / Adam Savage video!

[@Lskaggs63]

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!

[@Degr8n8]

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!!!

[@ComandanteJ]

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.

[@nathancarlisle2094]

I so want one of these now.

[@zymosan99]

sadly they are super expensive

[@chase0734]

SHUT UP AND TAKE MY MONEY!!!!

[@holysword876]

I was gonna say that :(

[@phalanx3803]

you got over $1000

[@therealzilch]

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.

[@MattMcIrvin]

I remember going to a party at one of my physics professors' houses in college. He had an Odhner calculator and he gave it to us cold and challenged us to figure out how to do long division on it. We got it in 20 or 30 minutes.

[@eddotron1224]

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

[@BearsThatCare]

+Edward Sim Probably give it a 2 for accuracy.

[@eddotron1224]

Bear McBear MC Hmm, infinite cred though

[@redbull5030]

Edward Sim you evil

[@melissacorrea8732]

I DO I DO I DO!

[@ari-cowan]

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.

[@SGManiac1255]

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

[@googelygoo1]

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.

[@DaffyDaffyDaffy33322]

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.

[@CCCPUTER]

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

[@oracleofottawa]

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

[@PrimusProductions]

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

[@oneonta310]

The world implodes.

[@Tursiopstruncatus]

Primus Productions Yes! Free energy!

[@Ruminations09]

+Primus Productions 0 to the power of 0 is just 1, though I'm not sure if the Curta would give the right answer as that's a more extraneous equation.

[@dementy9]

+PokemonTom09 numberphile has a video linked to 0^0, and its not 1

[@PrimusProductions]

PokemonTom09 'twas a joke.

[@lochinvar00465]

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!

[@ericfrancis7816]

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.

[@condorboss3339]

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

[@rhiannonk3176]

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

[@moikkis65]

i could sell one for you but if you check the price in ebay its pretty expensive

[@moikkis65]

+Renner just search curta calculator from ebay mine is bot for sale yet

[@ChrstphreCampbell]

You'll be able to print one up for yourself in a few years.

[@jlco]

+Chrstphre Campbell Hmm... we just need someone to design it in SolidWorks or AutoCAD, I guess. (Would 3dsMax, Maya, or Blender work?) Maybe I'll do it one day if nobody else has.

[@jlco]

kzbin.info/www/bejne/sJmVi2Rnos6EZtk Never mind. It's been done. Too bad the only 3D printer I would be able to get access to is almost certainly incapable of handling the size or precision of those parts.

[@madelinepoopoo]

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.

[@advgabe]

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

[@zappawoman5183]

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

[@chselegin]

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

[@danielstephenson7558]

Wouldn't that be something!

[@TheAviator226]

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!

[@avitalalef9947]

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

[@Joxzeth]

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

[@gavincurtis]

Divide by zero and it becomes a hand grenade.

[@livinginvancouverbc2247]

That blew my mind. I want one.

[@uzor123]

What a beautiful little thing. I'm astonished by all mechanized things, and this was pretty, clean and it was working really good! Great work on that machine seriously!.

[@spinal_capped]

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)

[@fryncyaryorvjink2140]

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

[@dillmon1]

That amazing object is the epitome of form and function

[@bazookamoose7224]

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.

[@SuperAaronbennett]

That is an amazing piece of Tech.....awesome!! Thanks for sharing!

[@Seabass20329]

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

[@AndrewTSq]

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!

[@Owlero]

When I first saw it I thought it was a modern revision. Truly timeless.

[@MichaelZola]

Very nice item, and very practical design

[@subliminalvibes]

Wow! I remember this from my childhood... My Dad had one of these and it's quickly apparent what an amazing device it is.

[@MarvelDcImage]

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

[@MattMcIrvin]

The Curta is digital technology! A slide rule is analog, but the Curta uses exact values represented as digits--decimal rather than binary as an electronic calculator would use.

[@rotwang2000]

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 ...

[@Sajedulguy]

Beautiful creation.

[@YesNowGoAway]

Wow, this is an absolutely beautiful machine.

[@thoranzalarvhazen4250]

A steampunk hipster's dream

[@babis8142]

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

[@servalcat]

It overflows--the most significant digit is lost.

[@thorham1346]

Truly a thing of beauty.

[@lohikarhu734]

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'...

[@miguelmouta]

And very soon the quantum computers shall be old dust .

[@tim8190]

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

[@clayton8or]

Rip offs dont exist unfortunately

[@Nebulae8]

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

[@Gorvinhagen]

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

[@DRnab1983]

There was one on pawn stars

[@Kibadda123]

How do you divide using that calculator?

[@servalcat]

The switch on the side changes the crank from adding to subtracting. With the switch in the subtraction position, it counts the cranks needed to drive the top register to zero. (You have to look at the register to see when you pass zero.)

[@ct92404]

David Fink I figured there HAD to be a way. Antique mechanical adding machines can also subtract and divide. Even though they're called "adding" machines, they did a lot of other operations by entering in "complimentary numbers" and using other tricks. It's amazing what these mechanical devices were capable of doing once you learn how to use them.

[@rahul327]

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

[@utl94]

What a stunning device, fantastic!

[@IanSan56]

But does it run Tetris?

[@Jarn73]

Very beautiful...but looks like a granade!

[@MyurrDurr]

I am so glad i am not the only who thought that! If you pulled that out in school you'd be kicked out

[@MattMcIrvin]

It's sometimes referred to as the math grenade.

[@jessstuart7495]

Pepper mill. Would you like some cracked numbers on your salad?

[@jdwatson6994]

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

[@KitsuKyo]

This is one of the coolest things I have ever seen. I totally want one now!

[@jjwarner9419]

Put 999999999 x 999999999 into it.

[@MrRtkwe]

+JJ Warner I did 99999999x999999999 (the turns counter only has 8 digits and I didn't want to count 90 extra turns for nothing) and the answer has overflowed (obviously) so the result register reads 999998900000001 which is accurate for the digits it can actually represent. The full answer is 99999998900000001 (I'll save everyone the trouble the Curta overflows the leftmost 2 9s)

[@jjwarner9419]

MrRtkwe You must be fun at parties.

[@MrRtkwe]

JJ Warner Didn't take long just 72 crank turns. It's a fast little machine.

[@matthewbolan8154]

+MrRtkwe Im pretty sure that isnt the right answer.

[@MrRtkwe]

Matthew Bolan You'll have to be more specific. Which number there's many in my post? The first one definitely isn't right it overflowed but the digits that were there are right. And the second is direct from google. Also notice I didn't do the exact number OP asked for because it's more than the turn counter will hold.

[@adoyaben]

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

[@Yggdrasil42]

I just bought one for €900 on eBay. Gotta be patient and you can usually get better prices on the smaller local markets.

[@AsymptoteInverse]

What a beautiful little thing.

[@jero37]

I'd known about these beforehand, thanks for reminding me of a beautiful piece of machinery.

[@javierreyna5321]

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

[@caseyhayes7510]

Javier Reyna it would overflow to zero then continue the calculation

[@servalcat]

It overflows--the most significant digits of the result are lost; the rest of the digits are correct.

[@jeanious2009]

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

[@TheOtherKT]

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.

[@David-lb4te]

A true enthusiast. Thanks.

[@JonWhitton]

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

[@KindGottes92]

Neutrik is making great plugs ther for stage-use

[@mx2000]

Hilti (hammer drills and other professional construction tools) is baed in Liechtenstein

[@GuanHuang216]

But... how do you divide numbers?

[@msolec2000]

Guan Huang Subtract until you get to zero, and see how many times was that. :)

[@GuanHuang216]

-_-

[@msolec2000]

Guan Huang That's how computers divide, btw.

[@spartanfoxie]

msolec2000 most computers have up and down shifters which can double or half binary values a more efficient way is to shift first then subtract making the calculation faster but using more memory like to times by 10 you shift x three times save to memory then shift x 2 times save to memory and add both of these together so unless a computer doesn't have shifters or maybe it has a barrel shifter allowing it to shift more than once at a time allowing it to do division even faster and no matter how high the number is in the same amount of time so there's no repeat until 0 otherwise large numbers would be slow and small numbers would be fast

[@msolec2000]

Well, that shifter is in the Curta too, the top carriage. It just multiplies by 10 instead of 2.

[@IYQ1317]

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.

[@DDazzle1]

I didn't even know that this thing existed. Thanks, numberphile.

[@ihathtelekinesis]

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

[@chainsawofdeath]

I see that you are also a big fan of matt parker's calculator reviews

[@rhamph]

Only 11 cred?! It's easily 20 or 30!

[@TheMrDemonized]

7,8/10 too much calculations

[@magnetar02p.23]

ihathtelekinesis no, you can definitely do more than just multiplication

[@OrlandoMGarcia]

ihathtelekinesis it can do all kind of division, substraction, multiply, square root, add, and factorize

[@acediamond5399]

BEAUTIFUL.

[@yutubenutzer]

Wow. This is really awesome

[@cresleyb]

Wow, I wish these were still in production.

[@MarcelKessler]

Wow dudes, thanks for this particular video. My math teacher had one of those and since then I couldn't find that thing on the internet. This piewce of engineering is just marvelous :-)

[@AlexBradleyPopovich]

Brillian idea!

[@balugovind]

a wonderful little machine. awesome engineering

[@Strifebtw]

Absolutely amazing.

[@thethirdman225]

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

[@devocodes]

Wow, what a simply amazing invention and masterpiece

[@suyogdani9305]

Beautiful !!

[@XouZ88]

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

[@lasaromorell3374]

This is sick, I've never heard of this level of mechanized calculator at this size in any books that detail the development of computation

[@nikolayrayanov2895]

This is amazing!

[@antman4400]

this is the coolest thing ive ever seen, it is now my life mission to find one

[@konstrakph]

Amazing invention! Wow

[@crazychris960]

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).

[@carlmmii]

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.

[@Yggdrasil42]

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 ;))

[@sirsanti8408]

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