Moral panic article from 1984 about the demise of slide rules

Not sure what they’re on about. You don’t need to know how the slide rule works so long as you know how to operate it. Put this number on the slide over this number on the fixed scale and read off the answer.

You do have to be aware of where to put the decimal point so there is some work involved.

Last thing I used mine for was currency conversions. You can punch in one operation on your calculator, but then they ask you, “Well, how about this much?” Set the scale once, read off the values they ask about.


I still have my HP12C on my desk. I don’t use it often. And per the article, the batteries need to be replaced. :slight_smile:

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Sure multiplication and division might be sexy, but it’s use will ruin our ability to add and subtract.


Oh, I loved those. Would like to find one. I have a few slide rules, including the one I used in high school. When I was a junior, in 1972, the first calculators became available (to the rich kids). And in college we used both calculators and slide rules. I wish I had my old programmable HP…

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An uncle gave me his slide rule when I was about 9, in 1969. Interesting toy.
A year later, we had one day in school where they showed us how to use one, for maybe an hour. And they gave us one to take home.
They haven’t moved since.
By the time I was in high school, the Bowmar Brain came out, and by the time I could get one, my prize ($99) was the TI-30, which I proudly wore on my belt in its little case.
(That did not go over well with mt larger classmates - life for nerds didn’t always emulate Young Sheldon’s experience)


Right to Repair has an ally in your old instructor.


Those calculators amused us 12 year old boys.



I’m in a similar situation. I inherited my dad’s collection of slide rules, and even though I don’t know how to use them, they are beautiful artifacts of his being an engineer. I especially love his circular slide rule by Dietzgen:



I believe even in 1984 there were solar-powered calculators. In fact, they were probably one of the first mass market uses of solar electricity.


I think my dad has that exact calculator somewhere. Has a big ol AC adapter.

The calculator I had was a cheapy solar powered one for most of school until my math classes too me to the graphing ones.

Man - I took calculus in HS but I remember next to none of it :confused:

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I found the pic on etsy. That one was listed as sold. More on ebay, going from hundreds to thousands $$$.

While on the subject, I still dream of finding one of these working and cheap somewhere. I think they are the coolest things.


My Venezuelan math/physics/chemistry teachers were sticklers about showing the calculation work so just putting down an answer would look suspicious to them. Sadly i learned late in HS that i’m slightly dyslexic when it comes to numbers, and i had a penchant for randomly changing numbers and/or plus & minus signs which explains why i struggled with solving math problems at times. I still will randomly misspeak numbers but at least i’m not getting graded :sweat_smile:




The next to last Texas Ins. (had insertable modules) I owned was stolen from me while at uni. I figure it must have been the “Oops, sorry” guy who popped in wearing a strangely poofy coat in mild weather. My calc was on a table in the adjoining room where I was doing work-study stuff.

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Back in the early 80s, when I was a pre-teen, my grandparents got me a subscription to something called “Things of Science.” Every two months I got a kit with supplies and instructions about something. The first month was aerodynamics, and it had a little balsa wood glider and instructions on experiments you could do with attaching paper flaps to the wing and tail. Another one was instructions on how to build a sextant, with a template to attach to thick cardboard, and mirrors. Another was a kit to build an abacus, and instructions on how to use it. There might have been a slide rule kit, but these are the only ones I remember.


Yeah, it’s like arguing that kids need to carry round a Rand McNally globe or a science fair volcano. The tools for learning something don’t have to look like the tools for doing it on a daily basis.

I’d say that no one is using the log button on a calculator without understanding what a logarithm is, and if they don’t remember how to use logarithms to do multiplication, well, that kind of is useless knowledge unless you have to use a slide rule.


When I took Chemistry in high school (this would have been '79-'80), the teacher handed out slide rules & made us use them in class; he didn’t allow calculators. His argument was allowing calculators was unfair to poorer students who might not be able to afford them.


I learned to use a slide rule…got a fancy K&E Log Log Decitrig Duplex for the engineering career to which I was being steered. When I finally shook it for illustration, where I belonged, the slide rule vanished into the detritus of the past. Today I have no clue what “log log Decitrig” even means. It looked cool, though. Trouble with slide rules, it seemed to me, is that their answers were usually an approximation. You had to estimate how far along the space between two hash marks the hairline was. I wondered how the astrogators in 1950s s-f movies managed to plot their courses with map, dividers, and slide rules. Guess wrong and you’ll never meet the Cat-Women of the Moon.

As for moral panics, I have somewhere one of Peter McWilliams’ how-to-use-a-computer books in which he loses it over those newfangled hard disk drives. Some of them store five, even ten megabytes of data! Imagine how many hundreds of pages of data you’ll lose if your Winchester drive crashes! Much safer to back them up to 20+ floppies.


I’m old enough to have gone through engineering school using a slide rule like this one. I still have it. The belt loop that clips onto the D-ring on the back is in perfect condition, because anyone seen carrying a slide rule on their belt would have been mocked mercilessly for the rest of their undergraduate years, if not their entire professional career.

The only arguments I have seen for the slide rule over the calculator are these:

  1. The slide rule is a reminder that more than three significant figures is dubious for engineering work.

  2. Since the slide rule doesn’t tell the user where to place the decimal point, it forces them to learn how to estimate the result of a long calculation. This serves as a check on whether the result makes sense. Calculator users tend to accept the result on the display, which may be out by orders of magnitude if they make a mistake entering the numbers.

That said, mumble mumble calculator mumble cold dead hand…

Here’s a great site for just about any slide rule ever made, the different scales, manuals, etc.

We can only aspire to the degree of nerdiness possessed by anyone who wears this working sterling silver tie clip and slide rule combo.