5.5 x 3.5 = 19.25 When using a slide rule, you tend to think about the numbers in a different way. 5 x 3 is 15 and 6 x 4 is 24, so you know your answer will have two digits to the left of the decimal point. This kind of familiarity with numbers is why I always like slide rules, and learning to use one seems to be useful in honing problem solving skills. Thanks for keeping one alive and the nice video on restoring it.

@rollerbald

Жыл бұрын

Thanks Ken! My background is in business, not math or engineering but I have always been fascinated by slide rules. My father always had one around and I have a EE friend who still uses his! You are so right about needing to be familiar with numbers in order to use a slide rule effectively. My mistake was due to inattentiveness! Thanks for the comment. Regards, Bill.

@charlesward8196

3 ай бұрын

This points up the problem with ALL calculating machines. You MUST have a grasp of estimation to see if your answer is reasonable. A little more than 5 times a little less than 4 will be about 20. People accept the answers from electronic digital calculators as Gospel, but if they input the wrong numbers, they will just accept whatever the little green numbers say to 10 decimal places. I am happy to report that modern elementary school math instruction with SOME curricula require students to ESTIMATE answers before SOLVING. I was introduced to slide rules 50+ years ago in HS chemistry, and the challenge was always “finding the decimal place.” This “native” math ability is fundamental to critical thinking on your feet when some politically motivated prophet is conning you into something that is not in your own best interest. The slide rule also required people to consider the concept of “significant figures” which means that your answer can be no more precise than your least precise input figure, i.e., if your least precise figure is to the 1/10’s place, your answer cannot claim accuracy to the 1/1000 ths place.

4:19 You got me there! I LOOOVE the smell of slide rule in the morning!

@rollerbald

8 ай бұрын

HaHa Martin! It smells like VICTORY!

Love the sense of humor. You did a wonderful job.

@rollerbald

Жыл бұрын

Thanks Jethro! Glad you enjoyed the video - I enjoyed making it. Best to you, Bill.

I still use my Mannheim slide rule. Neat video!!

@rollerbald

3 ай бұрын

Thanks for the comment! One of my best friends is a EE and he still uses his. Those things are fascinating to me. Best regards, Bill.

Nice job. I have been cleaning up a few slide rules lately myself. I find magic erasers (melamine foam) to be useful for cleaning the large areas. I do resort to scotch brite for tough-to-clean areas, just like you.

@rollerbald

6 ай бұрын

Thanks for the tip! I'm glad you watched the video and commented. Best regards, Bill.

Reaching down to smell your slide rule😂

@rollerbald

3 ай бұрын

HaHa! Yes I plead guilty to smelling stuff I am working on sometimes, especially after a shot of the good old Lemon Pledge! 😀Glad you watched the video and commented - thanks! Best regards, Bill.

What a blast from my engineering education past. One of my freshman classes was sliderule. And yes, I was one who had a post slidrule hanging from his belt. It wasn't until my junior year that the HP scientific was introduced and, because of the cost, not many students had the new HP. I took many a test with my trusty post sliderule.

@rollerbald

Жыл бұрын

One of my best friends is an EE and still uses his! You could always tell the engineering students because they had them hanging from their belts just like you. Thanks for the comment Big Mean Dog!

I have one of these that was my father's, bought new. It's still in very nice shape.

@rollerbald

Жыл бұрын

Hang on to that slide rule! They are a good reminder of a still useful technology and a family heirloom in your case. Thanks for watching the video and commenting, I appreciate it. Regards, Bill.

Regarding 11:13, 5.5 x 3.5 = 19.25 and not 192.50. This is because since 5 x 3 = 15 and 6 x 4 = 24; therefore the answer to 5.5 x 3.5 must be larger than 15 and smaller than 24. In a Slide Rule Course, the Mathematical Method that was taught for calculating very large or very small numbers was to convert them into their scientific notation in order to consistently keep track of their decimal points. For example, 5,500 x 3,500 = 19,250,000. This is because (5.5 x 10^3) x (3.5 x 10^3) = 19.25 x 10^6 = 19,250,000. Similarly 0.55 x 0.35 = 0.1925. This is because (5.5 x 10^-1) x (3.5 x 10^-1) = 19.25 x 10^-2 = 0.1925.

@rollerbald

9 ай бұрын

Thanks for watching the video and for the comment! Much appreciated! Bill.

@martinfiedler4317

8 ай бұрын

@@rollerbald "It's your responsibility to get the decimal point in the right place". Very well demonstrated 😉 And thanks for sharing this excellent restoration project! Will keep my eyes peeled, next time I am in the tool-section of a thrift shop 😁

Nice job! I got one of those rules off facebook marketplace and my case is to tight too. It is a great sliderule.

@rollerbald

4 ай бұрын

Thanks for watching and commenting Bill! I am always on the lookout for slide rules - guess I am a collector now. 😀Best regards from one Bill to another - I hope you will come back to the channel often.

my cursor frames have rusted and have turned to lace. I wish I could find replacement parts.

@rollerbald

10 ай бұрын

Search for 'slide rule replacement parts'. There are a few places that sell them. Thanks for watching the video!

I learned my high school math on a slide rule. By the time I got to college the HPs were on the market. I find slide rules at flea markets now and then. I think I'm up to 8. 2 are 6 inch and one is a model for EEs. Still looking for a circular model.

@rollerbald

Жыл бұрын

Hi Roger - thanks for commenting! I have several slide rules and actually used one a little in college although not as much as the engineering students. I have some circular ones inherited from my father who used them as a B-17 bombardier during WWII. I appreciate you watching the video! Regards, Bill.

@frankg3072

Жыл бұрын

Nice cleanup! The leather case came out really nice.

@rollerbald

Жыл бұрын

@@frankg3072 Thanks Frank! Glad you enjoyed the video. I may have gone a little overboard on the case, but it did come out pretty well. I like to do leather work, so I already have most of the supplies needed. Best to you, Bill.