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May I admit my ignorance and ask a burning question (or three)? What exactly IS a slide rule? What is it used for? How does it work? I saw one at the space center once, and I know that they used to be used for math of some kind, but that is my complete experience in this matter.

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If you are using a 1960s math book and there is a stand alone chapter in learning to use the slide rule, can you just skip it and use modern resources to figure out the calculations in the following chapters?

 

Yes. It is no longer necessary to learn to use a slide rule (it took a lot of practice, and we spent extraordinary amounts on it in school).

It is still neat to understand the principle how it works, though.

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May I admit my ignorance and ask a burning question (or three)? What exactly IS a slide rule? What is it used for? How does it work? I saw one at the space center once, and I know that they used to be used for math of some kind, but that is my complete experience in this matter.

 

The slide rule was used for doing computation before calculators. It uses the laws of logarithms. The most basic idea is:

according to the laws of logarithms, the log of a product is the sum of the logarithms. So, using two scales that are divided not in an equidistant manner like a ruler, but in a logarithmic way, you can add two logarithmic sections to obtain the product of the original number.

Likewise, you can do division as a subtraction of logs. Other scales allowed computation of square and cube roots.

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So, instead of multiplication you add logs, and instead of division you subtract logs? I'll stick with multiplication and division thanks. ;)

 

 

Yes, that's right.

But before calculators it was a very clever way - you put two sections of slide rule consecutively and boom, have a product :-)

Way faster than doing written multiplication with the standard algorithm, or long division.

 

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Vintage books don't use a slide rule. When were they invented, and when did they become part of high school math?

 

slide rules were invented in the 17th century :-)

 

I did not go to school in the US. We learned to use slide rules in Germany in school in the 1970s/80s. We did not have calculators until 10th grade (1983). We used tables fro logarithms and roots and such.

 

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Our high school chemistry teacher taught us very basic slide rule calculations in class in the early 1970s. I also used log tables in math class. Calculators were just coming into use. They were expensive and could not do much.

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May I admit my ignorance and ask a burning question (or three)? What exactly IS a slide rule? What is it used for? How does it work? I saw one at the space center once, and I know that they used to be used for math of some kind, but that is my complete experience in this matter.

 

Slide Rules work like calculators. But you have to know the scale of the number you are looking for -- IE are you looking for a number in the 10,000s, 100s, etc.  My physics teacher in HS made us use a slide rule the first semester so we got a LOT of practice in knowing what size of number we were looking for before we even did the calculation.  We used calculators the second semester. But I still remember the skills I learned that way.

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I feel like learning to use a slide rule nowadays is the math equivalent of being a "prepper." If civilization fails, how will we calculate large numbers without one? 

 

ETA: My mother told me she was in her school's Slide Rule Club. (and spelling sheesh!)

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If you are using a 1960s math book and there is a stand alone chapter in learning to use the slide rule, can you just skip it and use modern resources to figure out the calculations in the following chapters?

 

Yes. For some calculations you may need a calculator. Others you can do by hand, but they may be far more tedious than necessary. I would recommend using a calculator where you were told to use a slide rule, and otherwise doing calculations manually.

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I feel like learning to use a slide rule nowadays is the math equivalent of being a "prepper." If civilization fails, how will be calculate large numbers with one?

 

Either that or just an overabundance of nerdiness, which is why I learned :)

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TOPS Science has a unit called "Far Out Math" which teaches logarithms through building a series of folded-paper "slide rules" (only the last one is actually a slide rule). Great Girl really grasped logarithms after working through that unit. She likes to tell her instructors who ask about homeschooling that her parents didn't allow her to have a calculator until she'd built her own slide rule.

 

http://www.topscience.org/books/farout_math43.html

 

Free at http://www.nasa.gov/mission_pages/GLAST/main/education_outreach.html

(Scroll down)

 

I learned logs with tables rather than a slide rule, so I enjoyed the project as well.

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TOPS Science has a unit called "Far Out Math" which teaches logarithms through building a series of folded-paper "slide rules" (only the last one is actually a slide rule). Great Girl really grasped logarithms after working through that unit. She likes to tell her instructors who ask about homeschooling that her parents didn't allow her to have a calculator until she'd built her own slide rule.

 

http://www.topscience.org/books/farout_math43.html

 

Free at http://www.nasa.gov/mission_pages/GLAST/main/education_outreach.html

(Scroll down)

 

 

Thanks for sharing this information, Violet Crown.  I think my husband will enjoy sharing one or more of these projects with his tutoring students.

 

Regards,

Kareni

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We got to use basic calculators in 3rd form (8th grade) if we could afford them in the high import tax days. They didn't do logs etc but we had log tables. When I was at university in the 90's we had scientific calculators but I'm not sure what a graphing calculators are.

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TOPS Science has a unit called "Far Out Math" which teaches logarithms through building a series of folded-paper "slide rules" (only the last one is actually a slide rule). Great Girl really grasped logarithms after working through that unit. She likes to tell her instructors who ask about homeschooling that her parents didn't allow her to have a calculator until she'd built her own slide rule.

 

http://www.topscience.org/books/farout_math43.html

 

Free at http://www.nasa.gov/mission_pages/GLAST/main/education_outreach.html

(Scroll down)

 

I learned logs with tables rather than a slide rule, so I enjoyed the project as well.

 

:smilielol5:

 

Thanks for the link, but especially for the story!

 

My older son loves to say startling stuff like that. He doesn't have a single one-liner to compare with that one though.

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My dad used a slide rule but did not keep one. He has a book of log tables he showed us.

 

When my husband was first a pilot, they used a type of circular slide rule called a whiz wheel. He still has his but I don't know if they still use them anymore or if the new pilots are even taught how to use them with all the back up systems they have now.

 

They look pretty cool:

 

http://en.wikipedia.org/wiki/E6B

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When my husband was first a pilot, they used a type of circular slide rule called a whiz wheel. He still has his but I don't know if they still use them anymore or if the new pilots are even taught how to use them with all the back up systems they have now.

They still use them.  Dd had to buy one when she got her glider license.

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TOPS Science has a unit called "Far Out Math" which teaches logarithms through building a series of folded-paper "slide rules" (only the last one is actually a slide rule). Great Girl really grasped logarithms after working through that unit. She likes to tell her instructors who ask about homeschooling that her parents didn't allow her to have a calculator until she'd built her own slide rule.

 

http://www.topscience.org/books/farout_math43.html

 

Free at http://www.nasa.gov/mission_pages/GLAST/main/education_outreach.html

(Scroll down)

 

I learned logs with tables rather than a slide rule, so I enjoyed the project as well.

 

Thanks for sharing this I know what to torture, I mean do with, my kids this summer! Fun!

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They still use them. Dd had to buy one when she got her glider license.

For a glider, that makes sense as a back up. My husband said that in the newer large planes with multi system computerized backups, they are no longer issuing the whiz wheel or teaching students how to use it.

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For those slide rule fans.

 

Dh is currently reading out loud the book, "the brass dragon". It was published in the 60s. It is a good story that involves aliens, UFOs, ... And they have to use a slide rule to make calculations for space travel.

 

Many of the Heinlein books involve colonies on the moon, mars, etc. -- and yet still have people using slide rules for calculations.

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