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Math Hardware

Know How To Use a Slide Rule? 388

high_rolla writes "How many of you have actually used a slide rule? The slide rule was a simple yet powerful and important tool for engineers and scientists before the days of calculators (let alone PCs). In fact, several people I know still prefer to use them. In the interest of preserving this icon we have created a virtual slide rule for you to play with." Wikipedia lists seven other online simulations.
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Know How To Use a Slide Rule?

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  • by moosejaw99 ( 1052622 ) on Friday September 28, 2007 @12:49PM (#20784119)
    at around 10 years old. I've been using it ever since, and don't plan on ever stopping.
  • At least (Score:5, Funny)

    by edittard ( 805475 ) on Friday September 28, 2007 @12:49PM (#20784121)
    At least a slide rule is more accurate than excel 2007.
  • by pclminion ( 145572 ) on Friday September 28, 2007 @12:49PM (#20784127)
    I prefer to use a tactical nuclear slide rule [], myself.
    • by jdray ( 645332 ) on Friday September 28, 2007 @05:21PM (#20788179) Homepage Journal
      When I was in the Air Force (many years ago), I was a Loadmaster on C-130 cargo planes. Every aircraft had a sliderule as standard equipment, and we had to know how to use it to calculate load balances for the cargo, even though we used electronic calculators. The idea was that if our batteries died, we had to have a fallback. When the numbers you're dividing are seven digits for the numerator and four digits for the denominator, and your precision is 0.1, long division on a scrap of paper isn't reliable.
  • Of course (Score:4, Interesting)

    by Kozar_The_Malignant ( 738483 ) on Friday September 28, 2007 @12:51PM (#20784153)
    I did college physics, organic and physical chemistry with my trusty Pickett aluminum log-log slide rule. You needed one for real geek cred in those days.
    • I have a couple of Graphoplex slide rules [], a big G620 and a pocket G612. They are nice, but the plastic doesn't age very well, it has become yellow and brittle.
    • by Daniel_Staal ( 609844 ) <> on Friday September 28, 2007 @12:57PM (#20784271)
      I've never had one required (courses tended to require graphing calculators by the time I got to them), but I found one in my grandpa's desk and learned to use it. Then I carried it with me to high school and gave it to anyone who asked to borrow my calculator.
      • by arivanov ( 12034 )
        Same here.

        Worked a treat.

        As a matter of fact, it is probably faster to do some computations with it compared to a calculator or a computer if you know how to use it (I have forgotten it completely now) and if you are happy with its precision.

      • Re: (Score:3, Funny)

        by Agripa ( 139780 )
        I did the same thing with my HP-48 because my slide rules were too precious to risk in the hands of others.

        Student: "May I borrow your calculator?"
        Me: "Sure. Here."
        Student searches in vain for any operational familiarity.
        Student: "Ummm, no thanks."
    • Re: (Score:2, Funny)

      I grew up after hand-held calculators were ubiquitous, and after slide rules were rare. However, it was also before calculators were allowed on exams, but slide rules were! So, I learned how to use a slide rule. Later on, I was allowed to use a slide rule with all my useful chemistry and physics equations written on it, even though programmable calculators were forbidden b/c they might have formulas stored in them.
    • Re: (Score:3, Informative)

      by Rick17JJ ( 744063 )

      If anyone is interested, here are several links to downloadable ebooks and manuals for using slide rules:

      My only experience with using a slide rule was back in the 1960s in an 8th grade math class where we spent two weeks learning to use slide rules. We were just 8th graders, but were able to use a few basic features of something that was normally used mostly by scientists and en

  • back in the day (Score:2, Interesting)

    by OffTheLip ( 636691 )
    When I took HS Chemistry a slide rule was required. The instructor spent a bit of time explaining how to use it and we were quizzed later. While it lacked the precession of modern calculators we managed to solve complex problems. My dad earned an engineering degree back in the 50's using only a slide rule.
  • Mainly to give rough answers to vaguely complex calculations, to check if this or that engineering decision is sound, or not way off the mark. For me, that's the main interest of a slide rule today: not precise answers, but quick validation of a calculation. For anything more precise, I juse my trusty HP48.
  • Buy your own! (Score:3, Interesting)

    by PlatyPaul ( 690601 ) on Friday September 28, 2007 @12:52PM (#20784169) Homepage Journal
    In case you'd like to work with the real thing, take a look here [] for some info on places to buy slide rules these days.

    My mother recently bought one in a wave of nostalgia. I can certainly understand the physical appeal - the soft susurration of the pieces gliding against each other, the comforting grip of the leather carrying case, the art of perfectly lining up the dashes to the limits of human precision. If computers were that tactilely slick, nerds might rule the world.
  • by Blnky ( 35330 ) on Friday September 28, 2007 @12:52PM (#20784177)
    You youngsters and your simpleton slide rules. Try a real one that makes you use that noggin of yours. []
  • by the_humeister ( 922869 ) on Friday September 28, 2007 @12:54PM (#20784215)
    There's a reason we don't use slide rules, abacuses, buggy whips, etc. - we have better tools now. I used to have one when I was a kid back in the '80s, never really figured out what it was for, especially since we had scientific calculators instead.
    • Re: (Score:3, Interesting)

      by Skuld-Chan ( 302449 )
      I've always though about what would happen if the end of civilization were to occur and all your electronic gadgets (which require electricity) failed to work.

      If you wanted to rebuild society - what would you use? Yes - things like sliderules. Think of it is a method of survival, rather than - we have better why would you bother to learn how to use sliderules.

      One of the reasons I thought it was fun to learn morse code back in the day when I got my amateur radio license. Morse code happens to be the most fun
    • by Fred_A ( 10934 )
      I'm not sure about the rest but if you work with users for any length of time, you certainly end up using buggy whips quite a bit.
    • Re: (Score:3, Funny)

      by budgenator ( 254554 )
      There is this woman I know that really enjoys using a buggy whip.
  • Around here (Score:5, Funny)

    by Tarlus ( 1000874 ) on Friday September 28, 2007 @12:54PM (#20784217)
    The only slide rule around here is to not push the kid in front of you.
  • You see the article and think "the virtual slide rule I created is better than this one!" Too bad my University stopped hosting it (they stop hosting student web pages 6 months after you graduate).
  • Um No. (Score:4, Interesting)

    by VonSkippy ( 892467 ) on Friday September 28, 2007 @12:57PM (#20784269) Homepage
    I also don't know how to use a Flintlock rifle, trap/clean/spit roast a hare, catch a fish with my bare hands, hitch a wagon to a horse, or build/make/use a butter churn.

    Since I live in the 21st century, I don't really lose sleep over those things.
    • Re: (Score:3, Insightful)

      by pclminion ( 145572 )

      Sounds like if the global shit ever hits the fan, you're simply going to DIE, because you have no ability to care for yourself.

      Living in modern civilization is no excuse to be ignorant.

      • I think you severely underestimate peoples ability to adapt. If civilization as we know it were to collapse I'm sure most of the people on slashdot are intelligent enough to figure out how to survive on their own. Now if your argument was that they might not be physically fit enough to do so I might have to agree with you.
        • Re:Um No. (Score:4, Informative)

          by rubycodez ( 864176 ) on Friday September 28, 2007 @01:30PM (#20784763)
          actually, ignorant people in survival situations make all kinds of bad decisions and don't know how to treat or stabilize someone with injury. knowing poisonous from edible plants, cleaning properly cooking an animal without contaminating it, these are all things that people knew in that recent past but you'd better learn now rather than by trial and error (you die or are maimed for life if you're wrong)
      • by Rakishi ( 759894 )
        Actually you'll likely die no matter what you know. That's kind of "shit hitting the fan" in modern terms means, massive global death. Also since technology doesn't magically disappear when things go boom it's people who know how to REPAIR technological or mechanical items that will be in highest demand.
    • The veneer of civilization is thin, indeed. You never know how long the 21st Century is going to last. Get out of the basement and update your skillz:

      I also don't know how to use a Flintlock rifle

      That's pretty 18th century. You need to pick up the pace a bit [].

      trap/clean/spit roast a hare

      Again, you're a couple of centuries out of date. Get with the program here [].

      catch a fish with my bare hands

      Alfred Nobel has the thing for you [].

      hitch a wagon to a horse

      You actually do it the other way around (horse to

      • although in your case, given your apparent lake of experience with the things

        Damn, you lay the sarcasm on thick :)

        All I gotta say is, the amish are gonna pwn us all.
    • Re:Um No. (Score:4, Insightful)

      by hey! ( 33014 ) on Friday September 28, 2007 @01:39PM (#20784923) Homepage Journal

      I also don't know how to use a Flintlock rifle, trap/clean/spit roast a hare, catch a fish with my bare hands, hitch a wagon to a horse, or build/make/use a butter churn.

      If you were seriously interested in shooting, you'd find a flintlock pretty interesting; you'd have at least a rough idea of how to operate one, although it might take you a bit of time to use it expertly. You'd at least get some pleasure out of messing around with one, and maybe take some lessons back for shooting modern firearms. If you were seriously interested in cooking, you'd have a pretty good idea of how to clean, split and roast small game, or how to use a butter churn.

      If you are seriously interested in math, you are bound to find the slide rule intriguing.

      Aside from idle curiosity, it is also true that taking the difficulty out of processes is not always an unmixed blessing, especially in education.

      My daughter just started middle school, and one of the key math skills she is being taught is "number sense". This topic basically amounts to cognitive strategies for looking at a set of calculations and determining if certain possible results are reasonable. What is interesting is that this hole in math education was left by the removal of the slide rule from the curriculum.

      The brain is a curious and largely unreasonable thing; it obstinately refuses to work in ways that seem like it should, yet performs brilliantly in ways it seems impossible that it might. For example, when I was a student, I experimented with using a tape recorder instead of taking notes, on the theory I could play the lecture back during what otherwise was down time. Aside from the obvious deficiencies of only having audio, I was disappointed to discover that at least for me, listening over and over to information doesn't do anything for recall. On the other hand, I was delighted to find that if I wrote down information as I heard it, mainly concentrating on the speaker but letting my hands semi-automatically follow along, my recall was so improved I seldom needed to refer to the notes I was taking. Something about the process of completing the circuit from input to output caused the information to stick.

      In many other instances, I have found that trivial manual effort has unexpected rewards. I recently wanted to review probability theory, and I found it helpful to work through even trivial problems that I could see how to solve right away. It wasn't enough to have the insight, doing the work improved my comprehension and retention.

      The lessons in number sense given by the slide rule are largely of the same kind. You'd think you could do as well having a superior calculating tool that effortlessly gives you more precision than you need. All you need to do is ignore the superfluous digits. It may even work that way for you, but I suspect many people's brains won't acquire the same skills.
  • Made it through chem 1, chem 2, and physics back in the day. I keep it around in case there's an extended power failure...
    • In case you need to calculate how many cans of baked beans you can eat without killing yourself in a cloud of methane?
  • I graduated high school when calculators ran on 4 AA batteries and would run for up to 8 hours. They were just under $150 for one that could add subtract multiply and divide and the big bonus, a percent key for the morons who couldn't move the decimal point two places.

    I found the traditional slide rule large and bulky and often I would try to use the wrong index so my answer was off the scale off the other end (those who use them know what I'm talking about) so I was the owner of a circular slide rule. It
  • by netsavior ( 627338 ) on Friday September 28, 2007 @01:04PM (#20784389)
    the bigger the slide rule, the more accurate the calculation...
    • by snarkh ( 118018 )

      I presume you meant it as a joke, but it is true. You get more accuracy with a larger slide rule.
      If you double the size of the slide rule, you double the accuracy for most tasks.
  • by cliveholloway ( 132299 ) on Friday September 28, 2007 @01:05PM (#20784391) Homepage Journal
    "The index line on scale C is always put over the number to be multiplied on scale D"

    What's the point of explaining how it works if you don't explain what each of the terms used is?

    Damn nerds...
    • Re: (Score:2, Interesting)

      by ZERO1ZERO ( 948669 )
      I've read the site 10 times now - I still don't get how it works. Can someone explain it please. I'm not even sure I can even comprehend the instuctions. It seems to repeat it self - put the number on C over the number on D to be multiplied. Great done that - where's my answer.
      • by dereference ( 875531 ) on Friday September 28, 2007 @02:12PM (#20785449)
        I have nothing to do with that site, and as many others have mentioned there are far better virtual slide rules available, but I did learn long ago how one of these things operates, and the instructions in TFA are horrible even if you know what you're doing.

        First, the term "index" has the old-school meaning of the number "1" and it appears at either end of the C scale. On the left side of C it means 1, and the right side it means 10, but there are no actual decimal points involved (you're on your own for order of magnitude with this device) so they're equivalent at either end. Also, for multiply and divide, you don't need that hairline slider that covers all the bars; that's only useful if you need to align two values on non-adjacent rules. Just slide the center bar (the one that holds scale C) back and forth.

        The other important point to note is that you'll see numerals 1-9 between 1 and 2; those are just convenience markers for 1.1 through 1.9. That first (smaller) 2 you see, reading from left to right, is really 1.2 not 2.0.

        So to multiply 6x2, we can go either direction, starting at 2 and multiplying by 6, or starting at 6 and multiplying by 2. To start at 2, slide the center part of the bar so that the right-hand "index" (1) of scale C is directly above the 2.0 on scale D. Now to "multiply" you don't do anything; you just read the result, which is found on scale D, directly under the 6 you wanted to multiply. Here you'll see 1.2 is directly under the 6.

        Wait, though, we used the right-hand index, which is 10 not 1, so we need to multiply the result by 10. So 1.2 becomes 12 (which is why I said you have to do your own decimal point management). To start at 6 instead, slide the right-hand "index" (1) of scale C directly above the 6 on scale D; your answer will on D again, directly under the 2.0 of slide C. Again, we used the right-hand index of 10, not 1, so we multiply the 1.2 by 10 to get 12.

        How did I know to use the right-hand index rather than the left-hand index? Well, if you slide the left-hand index of C all the way to 2.0 on D, you'll notice that the 6 you need to multiply is off the edge of the device--an overflow, if you will--so you must essentially work with 10 rather than 1 and move the decimal at the end.

        With this extremely trivial example, you should be able to follow the rest of the terribly-written instructions FTFA for divide (although you can do significantly more with a slide rule than just multiply and divide).
    • Agreed.

      I read through the multiplication instructions, and I can't even come close to getting any kind of answer at all.

      The index line on scale C is always put over the number to be multiplied on scale D. The answer is then read off scale D, below the multiplying, number on scale C, using the cursor line for ease and accuracy
      e.g. set the 1 on scale C over the 2 on scale D (note: this is not the first 2 you can see as this is actually representing 1.2, it's the larger 2). You can now read off 4, 6, 8, 10 etc

  • (which I can, BTW, I stole my dad's many years ago, but I think it got lost in a random move), do you know WHY a slide rule works, and how to make a slide rule for addition and subtraction...

  • Of course (Score:5, Interesting)

    by Brett Buck ( 811747 ) on Friday September 28, 2007 @01:07PM (#20784433)
    I use a slide rule DAILY. It's an extremely useful and (if you know what you are doing) both accurate and fast. For many engineering problems 3 or 4 sig. figs. is plenty enough. The advantages are well-known - the most important being the elimination of "false precision" that you can get with a mindless calculation with a 10-sig-fig calculator.

        They are also just good things to have around. A good slide rule (Aristo, Nestler, Faber-Castell, etc) is just such a fantastically well-made device that you really need to see it to appreciate. The precision is something you don't see these days. Even a lowly Pickett is nicely made.

  • by sjvn ( 11568 )
    With 24 or so computers in the house, I still keep my now 30+ year old Dietzgen Polymath 1733 at my desk for quick math work. Like an abacus, if you really know how to use a slide rule, you can do basic math much faster than most people hammering on a calculator or PC numberpad.

  • What is the point of having such a long rule, if you only see a part of it and cannot move both parts at the same time???????

    At least, this one is usable: []
  • When I entered high-school I was using slide rules (still have some ranging back to great grandfather's). When I left high-school, programmable calculators were the rage.

    The E6B [] is still great for aviation.
  • []

    I still can't figure out how to use it ..
  • My freshman college physics professor didn't allow calculators on our exams, but he said we could use a slide-rule. So.. My dad lent me his and gave me a quick tutorial. I think I was the only student to show up with one. It actually slowed me down though (probably because I was still getting used to it).

  • I have (Score:4, Informative)

    by ajs318 ( 655362 ) <`sd_resp2' `at' `'> on Friday September 28, 2007 @01:16PM (#20784565)
    When my grandad died, he left his "old" slide rules to my dad and me. My dad kept the original wood and cellulose one from the 1940s; I got the plastic one from the 1960s / 70s.

    I soon got the hang of using it (and it can be quicker than a calculator sometimes), but I knew the general principle from before anyway. The main thing you have to remember is the slide rule only ever gives you the mantissa; you have to work out the exponent yourself. This means you have to do a rough mental calculation. People often put too much trust in calculators. When I was filling in order forms by hand in a previous job, I never used a calculator -- and I never got called out on a wrong total.
  • You have too much time on your hands. Why not simulate the abacus while your at it?! I study physics and I have not need for an slide rule. Matlab rules them all and everthing else is obsolete. I can't sit around all day doing mundane calculations. However, from my observations a tutor, calculators are being utilize too much in high school and the students suffer for it. It is one thing using technology to be productive and it is completely another thing to outsource thinking from your brain. Give them the
  • back in the third grade (roughly 1971-72). I was in my local Target when I saw a cheap plastic slide rule on the shelf -- we were just starting to learn multiplication, and the package said that it could do that, so I figured what the hell, and bought it.

    As promised, the slide rule was quite useful for multiplication and division. On the back of the slide, there were sine, log, and tangent scales -- that led me to look those things up in Dad's copy of Machinery's Handbook [], which got me into trig and pre-c
  • by fiid ( 4432 ) on Friday September 28, 2007 @01:21PM (#20784657)
    The E6-B is a rotary slide rule that pilots use for calculating wind correction angles, time/speed/distance problems, conversion between units (i.e. weight of a certain number of gallons of fuel), and fuel consumption.

    It's preferred over digital devices because they still work when the batteries go flat, they are easy to use with one hand, and some models are actually smaller. []
  • I'm 49 years old; In high school my math teachers still had 6 foot long slide rules hanging above the blackboard, but by the time I graduated I was the proud owner of a TI calculator. Within that 2 year (or so) span, pretty much everyone I knew made the jump from only using slide rules to only using calculators. I still, however, have my Kueffel & Esser, made of bamboo, ivory & glass
  • i was given one years ago, but somewhere along the way it was lost. does anyone know where to buy one?

    it'd be a cool thing to have.
  • I feel bad (Score:5, Interesting)

    by planckscale ( 579258 ) on Friday September 28, 2007 @01:28PM (#20784747) Journal
    My dad gave me his when I was a teen and said that he had used it for many years in college and the aerospace industry (Hughes). He gave it to me as a memento, and although he didn't keep it stuffed in his ass in Vietnam, it did carry a pretty significant sentimental value. It's lost; and although I did try to use it on several occasions, I only go so far as multiplication. It was a nice ivory color and had a leather carrying case. That thing probably helped launch 20 communication satellites.

  • Mildot Master (Score:5, Insightful)

    by dazedNconfuzed ( 154242 ) on Friday September 28, 2007 @01:31PM (#20784791)
    Slide rules are still in active use by - of all people - snipers. The Mildot Master [] is a sliderule for determining distances and ballistics for long-range precision shooting when using a rifle scope fitted with a "mildot reticle".

    Simple, low-tech, durable and cheap - specialized slide rules are still useful for particular applications where computers are expensive & fragile overkill.
  • I guess everything comes back, but only for people who didn't experience it the first time. Calculators became affordable (barely) when I was in engineering school. I entered with a slide rule and graduated with an HP-45 calculator. While I still have my old slide rule (which was my dad's before me) for sentimental reasons, there's no way I'd ever want to use it again. I couldn't wait to get my hands on a calculator in school, and paid what would be over $1000 in today's dollars, which was an enormous amoun
  • we used cuneiform on clay tablets. And the sexagesimal numbering system (base-60, but meanwhile cue puns...). Decimal is for wimps. You insensitive clods.
  • The sliderule was essential to my Dad's work, back in the day. He used it heavily in the thermodynamics engineering of jet engine parts, and later when working on the design of the Apollo heat shield.

    A good sliderule in the 1950s was ivory laminated on teak, ebony, or lignum vitae, with a magnifying hairline cursor. The wood was selected for stability despite changes in humidity: ideally it would never warp, crack, expand or contract. The ivory surface was needed for the fine, closely calibrated lines cri

  • I carry a circular slide rule in my briefcase for checking quick calculations and the various basic problems that pop up that are 'multiply/divide' ratio style problems. Here is a photo of this story's page [] along with my trusty CR-2 slide rule []. (Many basic items, from time and distance to power or area calculations.) The circular slide rule is still a basic tool used by pilots (when things that take batteries fail) and you can even purchase watches that have them built in from companies like Citizen, Seiko

  • As one of the geezers who had to fight for being able to use a slipstick in class, I'll point out that they teach something that more precise tools don't: estimation. Before you run a slipstick calculation, you must have some idea of the result. I've seen too many ludicrous results from uncritical use of a calculator.

    Now I think I'll go back to dozing on the porch.

  • by Alioth ( 221270 )
    I use an E6B circular slide rule for flight calculations. They are quicker to use than the electronic version, and have more than enough precision.
  • Vendors used to provide special-purpose slide valves to assist in sizing their euqipment. I still have one from Mason-Neilan for valve sizing that I used at least weekly.

    Especially when I need to check the valve sizes a gets the GIGO fancy pgm to spit out to 10 decimals.

    It is easy to slip decimals in general calcs on slide rules, so we used to be very careful about magnitudes. Electronic calculators keep everything very neatly, so we now lose a feel for magnatudes. The crutch becomes crippli

  • After a recent Incident [] in the billing department, verizon is rumored to be moving their entire accounting system to a series of mechanical slide rules that are operated by squirrels.
  • I learned how to use a slide rule for math competitions (I don't know what you Yankees had, but in Texas we had interschool competitions under an umbrella called UIL []). Unfortunately, I never got to compete with my newfound knowledge, because that year they phased them out, replacing them with competitions using a newfangled device called a "calculator".

    Yes, I'm old. Now git off'n my lawn, you mountebanks.
  • If Engcom is going to present an online simulation of a slide rule, why show a cheap-looking stock-issue Mannheim?

    Please, at the very least, show a Log-log Duplex Decitrig to illustrate the virile power of the device.

    And believe me, a slide rule was a badge of manhood (why do you think we carried them in holsters dangling down from our belts?) and there was intense rivalry and claims and counterclaims between the Keuffel & Esser faction and the Pickett & Eckel fans.

    But it was really no contest. I me
  • I was an English major, so there wasn't much cause for me to learn how to use a slide rule. I do, however, still have and use the English department's equivalent: a paperback Roget's Thesaurus.

    I think my dad has a slide rule somewhere still. Hell, knowing him, he probably still uses it.

  • I'm not sure about current training, but when I got my pilot certificate in 1999, *every* student had to learn to use an E6B [] circular slide rule to pass the written flight test. You can use a calculator or computer when you're flying, but to take and pass the written FAA test, you have to be able to run a mechanical slide rule.
    By that measure, at least 100,000 Americans know how to use a slide rule.
  • Oh yeah! Well... (Score:3, Interesting)

    by bynary ( 827120 ) on Friday September 28, 2007 @05:31PM (#20788295) Homepage grandpa just gave me the slide rule he used in school and it has a genuine "Made in Occupied Japan" sticker on the case. I can't remember the brand or model, but it's in a nice case and really is a beautiful thing. It is machined which is, according to the manual, much better than the painted ones. Just my two cents...
  • by fotbr ( 855184 ) on Friday September 28, 2007 @05:57PM (#20788553) Journal
    I'm a young'n, being in my mid 20s.

    Dad was an engineer. I learned how to use a slide rule for basic math in first grade, just because "it was neat" -- after all, if dad the engineer uses one, it must be cool.

    One of my math classes "required" a TI-82 (Jr. High), since some of the problems were of the "push these buttons in this order to graph this equation" type. After that, most kids went out and bought the latest and greatest TI graphing calculators. I was given a TI-86 when they were first released, as "the calculator that will do anything you need it to through college" by my parents. It was neat for a while, some of the games were cool, and programming in assembly for it was kinda fun - at least much more so than paying attention in Early American Literature. But I didn't use it for my math classes. I was the nerd in the back of the room using dad's old slide rule while everyone else was punching buttons on their calculators.

    I continued using a slide rule for most problems until my senior year in college, when I switched over to a TI-89 because I was extremely lazy and it made the statistics class much easier (it did all the work anywhere where we weren't required to "show our work").

    I still have it, and still use it out in the shop on occasion. My TI-86, TI-89, and HP-48G+ sit gathering dust.

Always leave room to add an explanation if it doesn't work out.