And now for something really off topic...

Larryjb · 01-13-2018, 01:22 AM

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 · 01-13-2018, 07:12 AM

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 · 01-13-2018, 09:00 AM

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/publicati...ller_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 · 01-13-2018, 09:06 AM

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 · 01-13-2018, 09:44 AM

Why buy a slide rule: http://www.antiquark.com/sliderule/s...lide-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 1978) -- it was the last slide-rule course ever offered there.

Larryjb · 01-13-2018, 09:53 AM

Quote:

Originally Posted by klpauba

Why buy a slide rule: http://www.antiquark.com/sliderule/s...lide-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 · 01-13-2018, 05:17 PM

Quote:

Originally Posted by Larryjb

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 · 01-13-2018, 06:33 PM

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** · 01-13-2018, 11:04 PM

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 · 01-14-2018, 11:14 AM

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.