How to Use a Slide Rule: Multiplication/Division, Squaring/Square Roots

[@MA-qz1sd]

Sorry bro but terrible explanation

[@codingforme]

true there

[@roberttucker1527]

ur a meenie @@codingforme

[@tycham85]

Came to the comments to see if I was the only one who thought this…

[@chillywilson]

yeah I'm sitting here with one I found trying to follow along and it's very much not the same.

[@michaelkuzelka8903]

Agreed

[@gedstrom]

I mentioned the term "Slide Rule" to a fellow engineer at work one time maybe 12 years ago. He didn't have the slightest idea what I was talking about. So, the next day, I brought in my old slide rule that I had used in my high school and college days starting back around 1964. There was a time when they were standard equipment for any engineering student and classes were taught on how to use them. Mine was a higher-end model and is still in very good condition.

[@robertaylor9218]

I just remember them being mentioned in “have spacesuit, will travel” and a few other stories, maybe early Asimov.

[@DrSamsHealth]

@@robertaylor9218 Heinlein's masterpiece is the one where I learnt about these :)

[@gedstrom]

Slide rules can give you much more of a VISUAL clue as to what is going on.

[@ColonelBen]

@@robertaylor9218that’s how I ended up here lol

[@warplanner8852]

"..so you have to know where your answer lies in the realm of numbers." That is one of the most beautifully worded descriptions of one of the basic tenets of using a slide rule effectively I have yet heard. Your explanation of this wonderful device is clean, concise, and extremely well done. Congratulations and thank you!

[@aorusaki]

wooow i see

[@androidlg7311]

Did we watched the same video? His explanation was terrible, it was hard to see where he was pointing, he would constantly switch from left to right which only makes hard to follow the operations and he would be talking about the "A" or "D" side of the scale but since the labels were be off screen there was no way to tell which is which. Basically what I am saying is, his explanation assumes the viewer know how to use one which is a very bad way to teach.

[@cache3d]

@@androidlg7311it needs true IQ to follow this 😂

[@microscopeguy011]

It was great to see you using a Faber Castell 52 / 82. I bought one just like it in 1973 for 1st year engineering... I continued to use it routinely ( but not exclusively ) for the rest of my working career. I admit they are a bit slower than calculators and require you to really understand what you are looking for. They also work to 3 significant figures but that is generally fine for engineering design needs. I now teach Mechanical Engineering and show it to my students. It's helpful for them ( I think) to understand that 3 sig figs that you really trust are better than 6 that you don't understand. Students make errors with calculators and then don't catch them because they aren't good at estimating the realm where the answers should be. I have seen many instances where slowing down a bit has saved me from making wasteful errors. BTW the slide rule originally cost me the equivalent of 2 hours wage at my part time job at the time. A calculator ( the next year when I thought about buying one) would have cost the same as 1 semester tuition. So I didn't buy one and used the $$ for food instead. LOL

[@anysnail6390]

Wait hold up. You paid $14.50 for a slide rule but a calculator would cost you $14,000 in today’s money. But I know you went to college in the 70s so you paid $3.60 for your slide rule and a semester at a state college then you would have paid $180 per semester.

[@microscopeguy011]

@@anysnail6390 HI. Not sure where you got your numbers ($14,000?) from, but here are the costs as I recall them. The sliderule was a very nice one on sale and cost just under $10. My wage was $4.80/ hr. The HP calculator was $350. ( apx) and tuition was about $300. A few years later, prices dropped, but by then I was working and my employer supplied calculators.

[@anysnail6390]

@@microscopeguy011 Ohio State University tuition including room and board for one year is $28,000. If you’re just talking tuition it’s only $12,000 a year.

[@microscopeguy011]

@@anysnail6390 OK. I see what you meant when you translated it into modern prices/costs. Yeah, from that perspective the money equivalent is crazy, right. I've of course seen this from my own kids and my students. I never thought of translating costs this way but it makes the interesting point (to me anyway) that minimum wage here in Ontario, is $15/hr (only a 3x increase) and tuitions have climbed by 8-10x.

[@microscopeguy011]

Oh, another funny (?) thought.....the cost of that first calculator was more that the cost of the used Beetle I bought for $250.

[@ElPasoTubeAmps]

I think the best explanation I ever had about the slide rule (and I had a dedicated slide rule course in college in 1967 and wore a beautiful Dietzgen clipped one to my belt loop) was from a professor that said, "what can you do with two sticks? You can add and subtract. That's it. But if you calibrate the two sticks with a logarithmic scale by adding and subtracting with the two sticks, you can now multiply and divide." and of course, some special scales for trigonometric functions. I was and still can be efficient with a slide rule (if need be) but I particularly remember that simple explanation. Thanks for the video.

[@SuperVpower]

+ElPaso TubeAmps Thank you!

[@zurviver_3747]

My grandfather just gave me his dietzgen slide rule from 1967! I'm brining a soviet one to college this year

[@kyla1567]

Cool! Thanks for the anecdote :)

[@7331MC]

Are we neighbors of 915? If so, what say you to meeting some time? I know near nothing of slide rules, but would like to from a person well experienced in it.

[@troublemaker9899]

Was just talking to my father about calculations he did in his early years as a engineer. He needed to pull up a the answers to some figures on a tower they were factoring into an equation, so he went into the library at Union Carbide to pull up the calculations which were done on the tower in 1958. Mind you, he's working on this in the late 70's, early 80's. So they pull out for him three four-inch binders where this guy had done calculations. They had to base the initial calculations on an assumption since they had incomplete data, and fill it in from there. 4-5 pages of calculations every single day to fill up these 4-inch binders on a slide rule, and after three months the guy finally found an answer, which was a guess. Which allowed him to begin the next set of calculations to find a better answer and so on. So this entire set of binders made up a literal year and a half of work with a slide rule to get a final calculation Well my father went down to the mainframe, and it took him a single day to put in the punch cards and run the same figures and calculations that took the slide rule guy in 1958 (Complete with a full team of engineering assistants) a year and a hald, and he had an answer by the end of the day. Now he does the same calculations in ten minutes at home, with no team, on a program on his laptop. It really makes you get an appreciation for just how far we've come. From a year-and-a-half to ten minutes. It boggles the mind, man.

[@skakdosmer]

I don't know this particular slide rule, but there must be some mechanical way of releasing the grip on the “tongue” (the middle part) while you move it, which is important, because you need to align the “tongue” extremely accurately. The “cursor” is not needed at all for simple multiplications. It is needed for squaring numbers or reading logarithms or trigonometric values, and it can also serve as a simple memory for intermediate results. By the way, by applying some rules of head calculations, you can in some cases get down to an accuracy of four decimal places. In your example 1.35 x 2.65 with accurate alignment it's easy to see that the result is a little below 3.58, so 3.57something. Now, when you multiply two numbers ending with 5, the result will always end with 25 or 75. If you remove the decimal points and the 5's at the end of 1.35 and 2.65 you get 13 and 26. Subtract one from the other you get 13 which is uneven, so it ends on 75. (Had it been even, it would have been 25) So it must be 3.5775.

[@JoeLinux2000]

Great post. You must be one of the men, not one of the boys.

[@saintmichael1779]

My Dad was an engineer in the 50's and 60's and was a whiz at slide rules. He taught me the basics of slide rule calculations

[@ryanrussell1051]

man. I have this old slide rule that I have deemed "different" and "wonky" following all these online tutorials on how to use it, and about 8 words of what you said made the concept "click". I can use this puppy now. thanks!

[@carlchilders4813]

You did a great job! I just had a 40th high school reunion and I got nostalgic thinking when I used the slide rule for competitions and I bought the same kind that I used back then. For speed purposes, we had to keep track of the scientific notation in our heads. I'd like to point out one thing in your video. You don't really have to worry about the "realm of numbers" when performing an operation such as 7 x 6. When the slide goes to the left for multiplication, you add one to the exponent. When it goes to the left for division, you subtract one from the exponent. For example, 7 = 7 x 10^0 and 6 = 6 x 10^0. When you add the exponents you get 0 + 0 but since the slide went to the left then you would add one which gives you 0 + 0 + 1 = 1 and the answer is 4.2 x 10^1 which is 42. Suppose we calculated 6/8. The slide is to the left so we would end up with 7.5 x 10^(-1) which is 0.75.

[@richardauchinleck1234]

Carl, very well and succinctly stated :)

[@carlchilders4813]

@@richardauchinleck1234 Thank you, sir.

[@richpotter]

My dad, who helped NASA put up moon missions, had a slide rule in his desk. All I could ever figure it was for was drawing a straight line. I dropped out of art school to become a circus clown. :) Thanks for the additional info!

[@Eggemeyers]

Slide rules were used beyond 1972 - pocket calculators were extremely expensive back then.

[@Eggemeyers]

Well that would depend on the size of the pocket, but they certainly had some that would fit in a pocket. Like the Sinclair Executive.

[@davidross1576]

My first calculator was a Readers Digest special offer in 1973. It cost $68 and had 6 keys: + - / * = %

[@xavierreed6952]

So this is how we'll do calculations in the post-apocalypse.

[@TaneemSanity]

What can you say about this boys video? kzbin.info/www/bejne/noukanimptqIpKc

[@Logic-ys7rw]

I can still just use my calculator. It's not like it needs Internet to work lol

[@bobrat]

This is how they did calculations for the space program before you were born .

[@minnesotajack1]

@@Logic-ys7rw The machines will enslave us and a huge EMP will be the only option. That calculator will aid in trying to harvest your organs for power creation. You should get a slide rule

[@NateGiebel]

@@Logic-ys7rwTell that to the coronal mass ejection or EMP.

[@mr.h5436]

Using a slide rule in high school separated the people who understood math from the chaff. I loved my slide rule!

[@Jonny2Jags]

I've arrived at this page now and then to refresh my knowledge on how a slide rule basically works and I have to say you make it fantastically EASY to understand...thank you very much. Will be looking at part 2 with interest....

[@srivers1]

Thank you for this video! I found my dad‘s old Versalog slide rule manufactured in 1951 that he used at Clemson College. It was cool to be able to get an idea of how it works.

[@DrTedEsq]

I taught myself how to use a slide rule, for basic calculations, in grade nine. This was the early 90's. We were allowed calculators, but I wanted to show off, so I did the slide rule. I've forgotten much of its use, so thank you for the refresher :)

[@andrewfrazer7829]

Superb, loved maths at school and Uni, my favourite teacher, Mr Lloyd, old geezer, like I am now [51] brought in his slide rule and passed it around in our A-level class. We, the school kids [not a student until college/Uni - damn Yankees] thought WTF, I had a Texas Instrument TI35 scientific calculator and was very glad indeed I did not have to use a slide rule. Never seen how it worked, to use modern parlance; it was in my 'bucket list'. So SuperVpower, you have helped me out and now I will watch part 2. 5*s, stay safe dude.

[@skakdosmer]

The first scientific pocket calculator in 1972 did not suddenly kill off all the slide rules. Of course not! Calculators were expensive, and people wanted first to see if they were really any good. In my high school slide rules were used until the summer of 1978. I know, because I graduated that year, and I was allowed to keep my “DIWA Rietz Ideal” slide rule, because next years students would be given Texas ti 57 calculators. (Chunky thing, 9 volt battery, really small red LED display, remember anyone?)

[@JoeLinux2000]

The first TI my school bought was around $300.00 and then the head of the department discovered it was giving errors in the results. My latest scientific calculator is an Android App that was free or $2.00 for the pro-version. I bought two different ones, because I didn't like the way scientific notation was entered on one of the them. One required the "shift" key whereas the one I like is direct entry of the "E".

[@elmoreglidingclub3030]

Excellent!! Thank you. I have bought a couple of slide rules and am having a blast learning.

[@ColdWarVet607]

Slide rules were in very wide use far far beyond 1972. I used them in Navy Nuclear Power School in 1977 and they were still used for several more years. The availability, size and most certainly cost put calcs out of the reach of the avg Joe until at least mid 80's. Very nice video, brought back alot of memories. They should still be used today, no power needed and you can get 3 decimal accuracy. We called them "Slip Sticks". We did alot of serious calcs with these like finding critical mass for Uranium and Plutonium, heat transfer & fluid flow, metallurgy and materials calcs,, all sorts of highly scientific but more importantly, dangerous" calculation that one might feel better using a precision electronic calculator for. Thanks!

[@carlosjaramillo3970]

I remember looking at my dad doing building structural calculations on this. Now he is 90 years old and is a full blown techie.

[@JanPBtest]

Very nice! At 3:27, it's definitely good to know the expected order of magnitude of the result (i.e, the position of its decimal point) but for lazy people there is a rule: the number of _decimal places before the decimal point in the product_ is equal to the _sum_ of those decimal places of both factors IF the slide had been extended to the LEFT (so 7 times 6, that's 1 dec. place + 1 dec. place = 2 dec. places in the answer, hence 42), and the same sum _minus one_ IF the slide had been extended to the RIGHT (so 1.35 times 2.65 would be 1 + 1 - 1 = 1 decimal place in the answer, hence 3.57...). For division the rule is similar except for subtracting the dec. places rather than adding and adding 1 rather then subtracting 1 when the slide is extended right (so 2 divided by 3, that's 1 - 1 = 0, no extra adding of 1 as the slide is to the left, so the result is 0.6...).

[@michaelnorman7094]

Now I know what they were doing in Apollo 13 since I'm watching it right now

[@Billy-uc8eb]

You need to use a pointer of some sort. I don't know where you are getting the answers.

[@JoeLinux2000]

He uses what is called "the cursor" to find the answer. That's the sliding clear part with a fine line. You have to follow along with your own slide rule, or there are virtual slide rules that work that you can find on the Web.

[@carlchilders4813]

The answers are on the D scale.

[@davidrandall2742]

I found my eldest brother's Hughes-Owens slide rule made by Sun of Japan, and found this video about doing some basic math on it: thanks. Come the apocalypse, this and my manual '84 Mercedes 240d will still be useful :)

[@mrpearson1230]

Took me 5 minutes to understand how you got 7×6 but I got it! This is cool!

[@tu-95turbopropstrategicbom55]

Awesome tutorial man, never quite understood slide rules until now!

[@TheSideband]

A Faber Castell Student slide rule, I had one of these for the end of my school studies and most of my college. Brilliant piece of kit. Many thanks.

[@ghesoonkarim602]

Thank you! I have one from Iraq/Baghdad high school time but forgot how to use. So I got it out to see how it works again comes with German language book and equation. Very interesting tool. 👌

[@virtuallyreal3055]

Thanks so much dude, that was really well explained! My gran gave me a slide rule a couple days back and I was pleased to find such a great video explaining how to use it!

[@trevcam6892]

That's exactly the same model that I purchased in 1961! I've still got it. I had just started my Engineering degree course at Polytechnic. We were never taught about slide rules in secondary school but we were very competent calculators using log tables. I don't know why we weren't taught about them in secondary school. I still used the slide tule for engineering calculations up until the 1970s when I purchased my first electronic calculator, although that would only do four functions, add, subract, multiply and divide. Therefore things like roots, angles etc still needed tables or the slide rule. I've still got that calculator as well and it still works. I recall paying about £80 for that calculator. By the 1980s slide rules were essentially dead. I doubt if any of today's maths teachers could use one or even use log tables for calculations. Slide rules are wonderful examples of how mathematics works (except add and subract). | did buy better slide rules after the first one because it became a bit floppy with continuous use. Still got those as well. I occasionally use them just for fun. I don't know what my beneficiaries will think of them or do with them when all my internal organic machinery finally fails. They will certainly have no idea what they are or how to use them.

[@d.barrows1326]

I got a Post slide rule when I started college in 1960. Later I put it in a case and hung it on my wall in my office with a sign: "In case of battery failure, Break glass". A couple years ago a young 3M engineer was in my office and saw it. "That is one of those a..a...a...a " "Slide rule" I said. "Ya, a slide rule. Do those things really work?" he replied. (They got us to the moon)

[@TCSC47]

You stated that the calculator took over from the slide rule in 1972, but I remember using my slide rule for a number of years after that. The first scientific calculators (forget Sinclaire's toyish calculator) were very expensive. I had access to my boss's HP scientific in 72 and it cost £100, That's £1350 in today's money!! Just googled it. Brilliant things slide rules.

[@erikwern144]

My Uncle- Carl Wern- received a patent in 1968 for his ABC circular slide rule which included decimal points. This "unfair" advantage led many school teachers banning its use in the classroom. BTW, I have a few of these slide rules in mint condition for sale.

[@yavrielsechelle7431]

Your posterity will probably put them in an antique store or thrift store. I've been seeing one at the antique store for a long time now.

[@douglaslastname2022]

Very good, thank you. I was never taught to use one, graduated HS in 74. I inherited my grandfather's slide rule and now I have a better understanding of numbers relative to logs sines and pi, better than what I was taught without it. It seems historically, the anticipation of computers was premature; The use of slide rules waned before any computers/calculators became available. That must have been intentional from top-down dictates commanded to the "education" system. Perhaps slide rules were shunned in order to sell computers/calculators more profitably; less thinking required: the dumber the better, just do what you are told...

[@OberonFaePrince]

Well done demonstration, and was quite helpful for my presentation. thank you!

[@antoniocunha1529]

I´m sorry, I didnt get it! Where are you reading the answers from? From D?

[@TCSC47]

Go to the beginning and see which are the C and D scales. Ignore all other scales. They are a distraction at this stage. He then lines up one of the numbers on the D scale which he wants to multiply, along side 1 or 10 on the C scake, whichever works to allow the second number being multiplied to stay inside through slide rule. He lines up the cursor with the second of the numbers and reads the number the cursor lines up with on the D scale. Hope this helps.

[@kirahen0437]

I found this in my great grandparents' house after they passed, and neither me or my parents knew what it was. I used Google lens and when I found out that this was a calculator I was flabbergasted! Thanks to this video, I can now do some of the basic operations on this, but I need to find another video to see how to do logs and sins

[@OneXRP205]

I think you should make a circular slide rule video

[@tomwatson9032]

Thank you very much for posting this... I was born in 66, so I have a vague memory of my brother using one of these at the university. It is absolutely fascinating, and honestly a little melancholy that such an ingenious device is no longer needed. One question: I don't seem to have an "A" scale. I imagine there are different types of slide rules, just as there are different types of specialized calculators?

[@SuperVpower]

Yep! I have seen some real small pocket slide rules with just a C and D scale on them. The A scale is pretty standard on "normal size" rules, though; it might be marked with a √ sign.

[@elvispresley3340]

HA - I was in secondary school when we changed over from using slide rules in maths in the early 70's to using electronic calculators. CHEERS from AUSTRALIA

[@CheapShotFail]

My dad always cites these things as the reason he didn't go straight into engineering out of high school in the early 70s despite having a high proficiency at it and ending up as one 10 years down the line. He got his degree after the calculators got more powerful. Now I finally understand why.

[@TheDeluche]

My dad was an engineer and he had a bunch of rulers and graphing tools. I didn’t realize that I’ve been playing with his slide rule as a child until recently. I just thought it was a fancy ruler with a plastic slider on it lmao!

[@TheGeezzer]

They're all worth $$$, some more some less, collectors snap em up, as no-one makes em any more. If its a _Faber-Castell 2/83N Novo-Duplex_ then its worth over $200...much more if its mint! The Japanese "Concise" slipstick is still made in small numbers.

[@jphili]

Omg so helpful. Most of the other slide rule tutorials are too disjointed, babbling and confusing to be useful. Thank you!

[@combatpig3435]

My grandpa was an engineer and gave me his so now I’m here

[@scada67]

The Wind Rises Movie brought me here.

[@NelsonStJames]

Good film! After seeing this comment, now I want to watch it again.

[@potassiumcyanide3857]

Kaze Tachinu had encouraged me to become engineer

[@obito7626]

Me too

[@ckenliesuboc9012]

Oh my! I thought I was the only one. Hahahahahaha. Anyways, I'm just curious of the ruler because I have seen any one of this kind of ruler here in the Philippines. It's really cool, though.

[@k3tarnin]

Me too

[@HebaruSan]

Thanks, this was helpful. I was trying to learn on an antique my dad gave me, but all the web tutorials just say to read the product off the D scale with no mention of the right-index trick, so my quest to calculate 4 times 6 kept hitting a dead end.

[@flairfilmsUK]

at 3.05 you say "4... and subdivision 1 and 2" and you point to 1.05 and 1.45 on the slide rule. So confused!

[@LenAdams]

I used a slide rule in school as late as 1978, a calculator cost more than a slide rule in 1978, and a calculator was waaaaaaaaay more expensive than a slide rule in 1972.

[@joseph_b319]

Graduated high school in 99. My Algebra teacher was an old-head who used slide rules. He showed us how to use one. Was lost the whole time. He went on how the slide rules are antiques and the best place to store them is in the trash can and to buy a good calculator.

[@McGavel1]

Thanks a lot! I love math a lot and my friend gave me a slide rule a long time ago, which I just found. I heard they can be really powerful tools, so thanks for the info.

[@SzoopaBeast]

watched quite a bit of these videos I think this video explains it the best .thanks for the info..fun tool to have

[@alanmakoso1115]

I'm a Gen Z born in 2003 with access to *really advanced* calculators like TI-Nspire and I'm still watching this video bc why not? What if the battery drains out and I don't have a charger nearby, gotta get backup

[@douglaslastname2022]

Slide Rulers should be brought back into the required standard curriculum in parallel with any digital system.

[@saadhith]

superb sir I really appreciate your efforts it was quite interesting.☺

[@jmweed1861]

Grew up using a slide rule for Calculus and Trigonometry

[@EC-gq4xx]

I just found my Dad's circular Slide Ruler. That's why I'm here.

[@augwa5645]

same its japanese and so smooth and it has a leather casing

[@christophertaylor4722]

I was taught how to use a slide rule in California High School in 1978. The pocket calculator was too expensive and not even allowed in school back then.

[@yatothinks4506]

I was inspired to learn how to use this tool because of the film called, The Wind Rises.

[@OvelNick]

The fastest airplane ever is the sr72 Blackbird. At 102,000 feet it was recorded to at 6.7x the speed of sound. It was engineered with ONLY a slide rule.

[@Hunar1997]

Is it still being produced? can i buy new ones? :(

[@geodavid51]

I used my slide rule several years after 1972 because the HP-35 was about $400, way way too expensive for a college student like me. Heck, it was the cost of tuition for an entire semester. I still have my slide rule but also have a second one, my favorite, a circular slide-rule. Not only couldn't you go off the end. And it had a little slot with a card with every formula known to man.

[@BTC_DNA]

I appreciate that you put this video together, BUT I **highly** recommend that you use an instrument that is smaller than your finger to point out numbers that are spaced in increments smaller than millimeters. For example, I recommend that you use a pencil, pen, or needle to point to the exact scale and number you are attempting to reference. Using your finger to point to such tiny numbers is like trying to point to individual grains of rice using a car as your pointing stick. I had to rewind the video several times to try to find the exact scale and number you were trying to reference. Much appreciated. Thank you.

[@petrofilmeurope]

Great video, thank you from Oslo.

[@laurencerilling5873]

You might have mentioned the reason for the left and right scales for odd /even digits. The left incorporates sqrt 10

[@LuckyLambikins]

Great vid, thanks! Any chance you'll make the trig slide rule vid soon? Also, the log log feature. Slide rules never made sense to me, but I'm fascinated by them. As someone earlier said, we used slide rules to get to the moon.

[@SuperVpower]

+Joe Libby Sorry, I didn't bring my slide rules to campus this semester. But Thanksgiving break is just around the corner so I'll have some free time and make those videos then!

[@SuperVpower]

+Joe Libby I finally finished editing and cutting it together! You can see the "Slide Rule part 2" video here: kzbin.info/www/bejne/bImXf2ish5KCaZY

[@TheGeezzer]

Nice tutorial and good camera work✔ I saw you slide the 10 over the 6 for the sum. I do the opposite and slide the 6 over the 10 for the sum🤪 The slide-rule is such a versatile lil critter. I've recently bought 4 of em off eBay for about 5 to 20 bucks a piece🤗 I'd love a Faber-Castell 2/83N Novo-Duplex considered the living God of slide-rules in usage, looks, style and build quality but they're MeGGa-BuX for a good one😲...and quite expensive for a dilapidated one!😖

[@Lonezewolflonewolf]

Do you think they will ever use these in today's schooling?

[@JoeLinux2000]

I think they should. Slide rules are fascinating. Simple ones with the C, D, Ci, and Di scales should be manufactured and used as learning tools in schools. They provide good exercise for the mind.

[@YoutubeisRubbish]

Did you hear the one about the constipated mathematician ? He worked it out in Logs

[@schneir5]

Wow I am really stoned because I found my dad's old slide rule and I was watching this video and I kept thinking that it looked weird and half of the letters were upside down and it took me way too long to realize that the slide part was upside down!

[@niaomi6]

I don't really understand how to use this. I think I'd have to be physically shown how to use one of these irl because this doesn't make any sense. But it seems you've helped other people understand so kudos for ya'll.

[@CafeFlamingo]

I have one with the original booklet and the leather pouch..

[@carltorjusen558]

l remember in 1972-73 Texas instruments came out with a calculator with basic arithmetic f(n) and was $129. l needed it for work. For addition one had to punch in numbers on the adding machine turn the crank and repeat the process to get an accumulated result when finished.. and hence the term crunching the numbers.!!.Almost my weekly salary...now one can pick them up for $1 and scientific for 2.5-3$ at dollar stores. The slide rule was almost known as the SLAP STICK..how's that for stiche...

[@TnseWlms]

In a nutshell: You can make an addition slide rule out of two yardsticks. To add 12+17, use the second yardstick to measure 17 inches from the 12 inch mark on the first, and you will see the sum is 29. The product of two numbers is the antilogarithm of the sum of the logarithms of the two numbers, so if the markings on the rulers are logarithmically spaced rather than evenly spaced, you can use the same principle to get the product instead of the sum.

[@brucelangridge6302]

Makes you use the brain to get the answer instead of just pushing buttons

[@melonslice1991]

Instead you're just sliding a bar... Doesn't seem all that different to me. If you want to use your brain get a pen and some paper. But that way we'll never get modern planes, rockets and ships built.

[@leotam3372]

Thanks, definitely easier to understand than the K+E manuals

[@JDvorak2009]

I don't understand

[@JoeLinux2000]

Siderules are somewhat difficult to understand. Using them takes practice.

[@brian4984]

Mind blowing.

[@jmaarten1]

Is there a list of definitions for the parts of the ruler? e.g.: 'cursor'. The video is hard to follow without an overview of the entire ruler and the terminology. It jumps into calculations without context.

[@MissT813]

Only thing I know about a slide rule is from the song *Wonderful World* by Sam Cooke

[@augwa5645]

i feel extra smart using a slide rule

[@MichaelMantion]

decent video. My recommendation to you is try to turn off the auto focus. if you are using a phone just download an app that allows you to turn off auto focus. then manually focus it and then use that spot to hold the slide rule

[@ironcladranchandforge7292]

I find the A and B scale easier to do multiplication and division. Try it and see what you think.

[@AdRenteria]

Maybe put a pencil to points your referencing? That would add a ton more expression in your video. I love it.

[@birdy369]

I still wish i could find a company who makes them nowadays

[@cesar9170]

this is basically a musical instrument

[@SWASTIKB306]

I got it as a gift from my grandpa , damn didn't know it was such an arcane product

[@vincentericbaraclan6055]

good day sir were can i buy a slide rule that you are using ?

[@_Mel_00]

For the cool stuff got to use Log Log scales!

[@johnguilfoyle3073]

Slide rules were used long after "the first electronic calculator was introduced" because not everyone could afford one.

[@emmanuelimobio8745]

this is quite easy to learn

[@HudsyBudsy]

Grandpa js mentioned this to me and had to see what the heck it was 😂

[@IPODsify]

im sorry as soon as you got to the subdivision I got confused. Where's the 1?

[@prof.dr.abronsius8939]

I have a 'pi' on the logscale itself, and an 'e'; but what does 'c' mean?? It seems to have the value 1129...

[@willjohnston2959]

The c value about 1.128 is used for finding diameters of circles with a known area. It works out to 2 * √(1/π), and is the diameter of a circle with area 1. π * r^2 = 1 r^2 = 1/π r = √(1/π) d = 2√(1/π)

[@karhukivi]

@@willjohnston2959 There are some other useful marks like C1, M, and a symbol like a small "q". C1=sqrt(40/pi) = 3.57; "M" is 1/pi = 0.318; and "q" = pi/180 = 0.01745 C and C1 are used for area of a circle calculations, M makes calculations with pi easier and the "q" is for radian calculations.

[@formerunsecretarygeneralba9536]

3:02 watched this part like 5 times I still don't understand how you get 42. I know how you get the first number but where does the 2 even come from?

[@RossDuClair]

Good instruction. A suggestion for future tutorials: do not use auto focus on your camera. Looking at blurry numbers is just no fun.

[@amateur2521659]

I have the same device and try to understand how to divide 70 by 90 with slide rule? )

[@grimgrimxv9380]

Hi, I have a pickett 120 and when I tried to do the 1.35 * 2.65, I got 3.05, can you please tell me what I did wrong?

[@Leverquin]

Have you ever used Curta?