And now for something really off topic...

[Larryjb-HILO]

As a teacher, I'm really troubled by the worsening skills of the students I teach. Throughout the entire profession globally, academics in teaching and teachers themselves always seem to believe that more technology will help students learn better. In some cases, this is true. In many cases I believe more technology is handicapping our young more and more.

Students have no concept of numbers and teachers believe the problem is spending too much time on memorization, so they make kids struggle with complex abstract math concepts as early as grades 2 and 3 (I know because I saw it happen).

I grew up just as calculators and computers were hitting the regular consumer. My older brother and sister learned to use slide rules, my father used one regularly. Now, 35 years later, with all the digital scales, my students have an impossible time trying to understand uncertaintyand significant figures. The slide rule forces the student to think in terms of uncertainty. It also forces the student to use his / her brain to think about the numbers being manipulated.

I've decided to see if I can challenge myself to become faster on a slide rule as on a calculator. While I don't believe I'll be able to achieve that, I may be able to achieve greater accuracy on the slide rule because I won't be tapping wrong keys. This always plagued me on the calculator so I had to run all calculations 2 and 3 time over to check. I suppose one can set the index wrong on a slide rule.
I just received a Picket N-803 ES and will be having some fun with it. My 12 year old is interested too!

 

[Padgett]

Mine was a K&E.

Ever see the movie Idiocracy ? Bad movie but a fascinating premise: modern life is breeding out intelligence.

Always enjoyed math though did have trouble with thermo and calculus since are approximations.

When I was growing up school was 8 to 4:30 with 1/2 hour for lunch and an hour for PT. Almost all classes with an occasional study hall. How much teaching does a student get today ?

ps scored high on the SAT and guidance councilors figured I had to know some calculus. Just knew how to figure the speed and 1/4 mile time for a dragster.

 

[Larryjb-HILO]

It sounds as if your school had a strong academic focus. Probably many of the non-academic kids would have dropped out by grade 8 or 10. What did the rest of your day look like? Many of our students have sports games or practice that begin at 3:30 or 4:00 and go for another couple of hours. Also, if our school went from 8-4:30, many of the non-academic students wouldn't be able to hack it and would drop out.

In North America, we often criticize the integrated model where all types of students are placed into the same classroom. The reasons behind this criticism is that some students who might have been streamed into a trade mature a year later and can become strong academics. In the older streamed system, they were then stuck in the trades. I do believe that there are good arguments for streaming around grade 10, though. Some school systems allow students to take a year off at grade 10. This can give the student the dose of reality, then return to an academic stream if appropriate.

This:
http://www.cogtech.usc.edu/publications/kirschner_Sweller_Clark.pdf
is also good reading.

I have to work with the system we have. A slide rule would be too complex for many students in a main stream education system. However, I believe calculators have no place in a school at all until grades 9 or 10. All the math they need to know can be taught, practiced, and tested with problems that don't require the use of a calculator. When I was in school, the problems were designed so that they would work out conveniently when done correctly. In fact, if I started getting weird decimal answers, I knew I did something wrong.

In an academic stream, a slide rule will force students to think about magnitude when multiplying numbers. That is something I am weak at, in part due to the use of a calculator. I am aware of approximate magnitude, but if I see two numbers, for example 83 x 4.9, I neglect to account for the fact that another magnitude of 10 is introduced when the 4 is multiplied to the 8. I tend to trust the calculator. Part of the reason I'm going to play with the slide rule is that I will be training myself to recognize that my answer will be in the 400's instinctively without having to think of it.

I'm sure my wife and others who were raised without a slide rule will be laughing at me. I was never raised to use a slide rule either, but if I can get my kids to use one effectively for multiplying and dividing, I'll bet it'll help them immensely.

 

[Larryjb-HILO]

As for being bothered by approximations, the approximations in calculus are more theoretical than practical. I can see the approximations from a slide rule being more troublesome. They are good to 3 significant figures, but the error for multiple calculations can propagate and magnify as more calculations are performed. In my senior classes when I teach significant figures, I tell students to carry an extra digit (a 4th digit if 3 sig figs are required) to prevent compounding of rounding errors.

For many modern technologies where we have the ability to measure up to 4 and 5 significant digits, the common slide rule just won't be enough, although I've heard about spiral rules that will give more.

 

[klpauba]

Why buy a slide rule: http://www.antiquark.com/sliderule/sim/virtual-slide-rule.html ?

A few online sites have courses: http://www.sliderulemuseum.com/SR_Course.htm.

I took a slide rule course my second year of college (first year of engineering school in 197 -- it was the last slide-rule course ever offered there.

 

[Larryjb-HILO]

Why buy a slide rule: http://www.antiquark.com/sliderule/sim/virtual-slide-rule.html ?

You have to be sitting at a computer. I can play with a real slide rule anywhere. AND look geeky! (Where can I buy pocket protectors?)

Oh, I bet our TM was originally designed using a slide rule.

 

[Padgett]

Oh, I bet our TM was originally designed using a slide rule.

Doubt it, HP35 came out in 1972 & just needed to know RPN. By '75 TI had both scientific and Hex calculators (TI Programmer), soon followed by the Commodore and I had a scientific shaped like a slide rule & one in a wrist watch (Casio).


So by the early 80s, scientific calculators had replaced slide rules about everywhere.

 

[Larryjb-HILO]

That may very well be true. I have heard of some engineers sticking to their slide rules up into the 2000's.

I started using RPN in highschool for fun, but never had access to a slide rule. (My dad wouldn't let me touch his!)

 

[Bailey'sMom]

Interesting discussion

Hi Larry I think a lot of the stuff you mention depends upon what age you are.

I graduated high school 1982 I suspect that Padgett probably graduated oh say 60 years or so ago am I right? When I was in middle school calculators were just starting to be used and I believe by high school that’s pretty much all we used.

I still struggle to do multiplication and division longhand on paper or quite frankly Using just my brain. My father on the other hand who was born in 1931 could do math like nobody’s business in his head or on paper - you name it he could do it. He only had an 8th grade education. He couldn’t understand how I couldn’t do math that quickly. And I blame the calculator and I think it would make a lot of sense for kids these days like you suggested earlier to not be able to use the calculator until high school.

I now work with numbers every day and still don’t trust myself to use anything other than a calculator and if it’s not my trusty 10 key with print turned on, then I have to verify multiple times.

Oh and I never used a slide rule either, no did I take calculus. But give me an excel spreadsheet and watch out.

I really believe kids these days are totally distracted by all the electronic devices that they use, video games, TV etc. I also find that a lot of parents tend to over shelter their children at least when it comes to finances and how that works.

 

[Larryjb-HILO]

I agree with you on all accounts. The calculator has removed so much "thinking" that I have kids using the darned thing to determine 5x0 Or, they accidently type in 35 x 2 instead of 3.5 x 2, and write the result as 70 not thinking that the result should be a single digit answer.

My point regarding the slide rule is directed more towards students of science. It supports so many key science skills. If it were taught (and its use mandatory) students would have an innate sense of significant digits, error analysis, estimation, and even pure measurement. You can't imagine the resistance I get trying to convince the students the concept of measurement error.

However, most people would probably think I'm nuts to make all students use a slide rule exclusively for science!




Padgett, where did you get your high school education? Was in in the US? My dad was in high school during the 40's, and I don't recall him saying that he was in school from 8-4:30. In China where they spend long hours in school, some of those hours are tutorial classes, so it's not always new information.

 

[BrucePerens]

I have been on the faculty of three colleges and other stuff you can read about in Wikipedia. My public school didn't even bother to teach me to read, as I was considered to be "retarded" due to a speech impediment. Fortunately my parents got a lawyer. But I am not a product of formal education, and probably am better off for not being one.

The schools teach the wrong things and simply perpetuate another generation of wage-slaves who can't figure anything new out, but the ones who were "good students" can sure do their arithmetic! Spelling bees are perhaps the greatest demonstration of misapplication of education.

Students should not be made into little flesh adding machines, but should learn the principles of math and science so that they can apply them when necessary. There is no merit to memorizing something you can get from a book or a machine. There is merit to being able to use what you know to solve a problem, without having the process explained to you first.

Look at any primary school today, no matter how good, and you will see students being taught algebra without first being taught to program! What is the POINT of algebra if you can't progam? You can't APPLY it and you are so powerless to use it that it's 100 times harder than it should be. Ask the teachers why kids aren't taught to program first, as I have, they say it's a good question and they have no answer. It's like being taught Russian grammar without ever being taught Russian vocabulary, so you can pass a test afterward, but never speak the language.

 

[Bailey'sMom]

, but should learn the principles of math and science so that they can apply them when necessary.

There is no merit to memorizing something you can get from a book or a machine. There is merit to being able to use what you know to solve a problem, without having the process explained to you first.

So true. I may not be the sharpest tool in the shed but I sure can work things out logically. I can apply my knowledge to different situations and work my way through to a good conclusion. It’s amazing how many people are book smart but cant find their way out of a paper bag.....

 

[Shane826]

What do you mean by programming in relation to algebra?

 

[BrucePerens]

What do you mean by programming in relation to algebra?

There are a lot of elements of algebra which seem quite abstract until computer programming makes them concrete, for example variables and functions. Indeed, if you can teach a plotting API, pretty much every mathematical operation becomes more concrete once you can program it, for example look at the way this links the sine and cosine functions to the appropriate waveforms, with the proper phase offset from each other, and to a point on a rotating wheel. But probably the most important thing you learn is that any algorithm you learn can be embedded in a function and then becomes very simple to reuse, potentially for the rest of your life. I gained applications for all of these mathematical things when I got to work on computer graphics and signal processing, but algebra was very abstract and not terribly useful until then. The actual programming is not rocket science and kids are taught "turtle graphics" today which would render most functions. Most people would learn better if they learned simple software applications of the mathematics they were learning.

 

[Larryjb-HILO]

The last few posts exemplify just how important it is to not swing too far to one side or the other of pedagogical techniques. It is important to experience concrete applications to the abstract (such as algebra), but as teachers, we mustn't forget the importance of memory.

My reference to the slide rule was more towards young and upcoming scientists/engineers. Many of my students have never seen an analog scale as they all have digital watches, many teachers use digital mass scales, and with the push for more technology yet, they will be seeing digital motion sensors, etc etc. In fact, the digital age can make what should be a concrete example more abstract.

Going back to my comment about the Trailmanor being designed using a slide rule, check out this page for a reminder:
http://www.woodallscm.com/2001/10/trailmanor-inc-2/

Hulsey built his first "Trailmanor" in the early 1970's. He was probably designing it in the 1960's. I'm sure, for his day job, he had and knew how to use a slide rule. That's why I think the TM was originally designed using a slide rule. By the time he was designing the version for the consumer market, he may very well have been using an electronic calculator.

 

[tentcamper]

Just about all engineering was done with slide ruler until somewhere in the early 70's and 1980's. The exception was NASA and aerospace companies, which had some limited use of computers back into the 50's and CAD design tools.

So the next time you are crossing a bridge built before 1970, inside a building build before mid 1970, you are counting on an engineer sliding his ruler correctly and guessing at the fractional distance.

 

[tentcamper]

I have been on the faculty of three colleges and other stuff you can read about in Wikipedia. My public school didn't even bother to teach me to read, as I was considered to be "retarded" due to a speech impediment. Fortunately my parents got a lawyer. But I am not a product of formal education, and probably am better off for not being one.

The schools teach the wrong things and simply perpetuate another generation of wage-slaves who can't figure anything new out, but the ones who were "good students" can sure do their arithmetic! Spelling bees are perhaps the greatest demonstration of misapplication of education.

Students should not be made into little flesh adding machines, but should learn the principles of math and science so that they can apply them when necessary. There is no merit to memorizing something you can get from a book or a machine. There is merit to being able to use what you know to solve a problem, without having the process explained to you first.

Look at any primary school today, no matter how good, and you will see students being taught algebra without first being taught to program! What is the POINT of algebra if you can't progam? You can't APPLY it and you are so powerless to use it that it's 100 times harder than it should be. Ask the teachers why kids aren't taught to program first, as I have, they say it's a good question and they have no answer. It's like being taught Russian grammar without ever being taught Russian vocabulary, so you can pass a test afterward, but never speak the language.

Bruce I think programming is a very good way to learn a subject because you have to learn the subject and rules to program it. But I think there are many other ways to learn a subject, but you have to be interested in learning the subject. That is the problem. To many teachers its a job, there are very few gifted at teaching. I think too many teachers were in the 10th or 11th grade and trying to decide a career and like the idea of 3 months off a year.

Many teachers today don't generate interest and/or make it fun to learn. I can look back at my education which included grad school. There were only a handful of teachers that generated that interest and I would consider a true teachers. I remember their names. The other I could not tell you their names. I was lucky, I had a curiosity for science and had my curiosity encouraged by some very bright people that were family, friends of the family or friends.

 

[Larryjb-HILO]

...
So the next time you are crossing a bridge built before 1970, inside a building build before mid 1970, you are counting on an engineer sliding his ruler correctly and guessing at the fractional distance.

Nowadays, when you cross a bridge built in the last 30-40 years, you are counting on the engineer to be tapping the correct buttons on the calculator, not press a 2 instead of the 5 in the exponent of the exponential notation, and have a weight limit off by a factor of a thousand. Those good with the slide rule would spot that error of magnitude straight away because keeping magnitude straight would be second nature on a slide rule. My students, even the best, tend to trust the "blackbox" calculator too much.

Then, there is guessing at how many sig figs in an answer that contains 8 or more digits ona calculator. If you mess up and think you have more sig figs than you should, you can have disastrous results. Truncation errors caused a computer to miscalculate an anti scud to miss an incoming scud, killing American soldiers. These errors could occur with the slide rule too, but I think many people rely too much on the calculator answer.

I was not brought up on the slide rule, but I envy the second nature sense of numbers my elders had.

 

[Larryjb-HILO]

...Many teachers today don't generate interest and/or make it fun to learn. I can look back at my education which included grad school. There were only a handful of teachers that generated that interest and I would consider a true teachers. I remember their names. The other I could not tell you their names. I was lucky, I had a curiosity for science and had my curiosity encouraged by some very bright people that were family, friends of the family or friends.

As a teacher, I am plagued by the politics of the profession, students who just want an easy A so they can get into university. I know this has always been the case, but I have seen it all get worse in the iphone/smartphone era. When I was confronted with a tough problem, I took a long walk and let my brain muse over it. I could usually have that good feeling of success when I got home and figured it out. Now my students plug into their "soothers", the dumbphone.

 

[kempert]

Larryjb -

You hit it right on the head when you mentioned "smart" phones. I work with high school student/athletes in an environment where many of them are on track to work in the medical field (doctors, research scientists, etc.). I thought it was just me being an oldster (69) when I thought they seemed to be getting "dumber" in recent years. Young professionals (early 30s) are telling me that the phones have led to young people not thinking. "When confronted with any problem or question, they just reach for their phone. We have an "electronic free" zone for about two hours each day. If they try to use one during our time, I take it (after one warning) and just start "messing" with it. The word has spread and we have no problem. Now, if I can only figure out a way to stop my co-worker (23) from constantly using her phone during our time.