18ths would need two divisions by three, but thankfully dividing a known measured length by three is easy with a piece of string.
what kind of cartoon fantasyland do you live in where it’s easier to find a piece of string than it is a calculator?
also, all of this is assuming you have your drafting ruler to hand
do you carry it around with you in your pocket on a day-to-day basis? some deep fucking pockets you’ve got there, although I suppose you already that to the 1/24th inch
They can be measured, calculated and double checked
my guy, we’re talking about accuracies of millimeters here: you’re not “double checking” your 12" ruler is accurate by slapping your bare carpet gripper up on the drafting table
well, considering i was sitting in the bathroom looking at my phone while wearing clothes when i saw your response, i’d say string and a calculator were both equally close at hand.
only one of those can be used as a measuring tool, though… I guess you could mark off how many calculator lengths something is and measure it later. ngl, i hung a shelf using that technique once, but i wouldn’t use it to find one third of a length. the nice thing about string is that if you don’t have a measuring stick you can always stuff it in your pocket and measure it later when the appropriate tool is at hand.
apologies for any confusion about checking measurements, i wasn’t referring to using my own foot to verify the length of a line, but the common practice of using fractional mathematics to make and verify calculations thousands of years ago and to this very day. we have records of this method being used across language and unit barriers in the ancient world.
there’s another post earlier itt blaming the mars climate orbiter failure on sae unit conversion but nasa puts the blame on itself for not double checking the software and measurements they got back from lockheed. I remember back in the day hearing about that failure on the news and seeing how it was not a problem of difficulty of conversion between the compound units involved, but failure to actually convert between them at all!
since you brought up calculators, there’s a salient point to be made here using a long winded anecdote: when i was in school there was a point in time when suddenly teachers began providing calculators for the exams. this wasn’t that magic moment when the mathematics became just too complicated to expect a middle schooler to do it all on paper. last years class had to use longhand, this years class were provided little blue texas instruments scientific units with a ten digit display and helpful guide to performing logs and other operations that would have been taught using super and subscripts glued to the inside of the cover that would be taken back up at the end of the test.
this didn’t happen going from one grade level to another, but right smack dab in the middle of the academic year. a whole classroom of students yanked bodily into the digital age.
when the parents found out you’d think the questions were gonna be written on the proctors inner thigh. “i had to do it by hand, my kid should too!” “you’re supposed to be teaching them math, not how to use a calculator!” and it’s sister “you’re supposed to be testing their ability to do math, not use a calculator!” but the most common one by far was “they’ll all just get the right answers and we won’t know who studied and learned.”
when the grades came in there was almost no change from last years class.
there were some individual students who did better or worse than their test history would suggest and a whole bunch of new common wrong answers, but by and large aside from errors the ability to perform calculations in response to a prompt was unaffected by ten signed digits of precision.
how could it be that a calculator made no difference?
it turns out that understanding what a question was asking for, verifying ones work and recognizing wrong answers that needed to be rechecked couldn’t be performed by the little blue rectangles.
and many years (and measurements) later i have the same outlook about metrology: comprehension of the goal of a measurement gives you a much better chance to get it right than a calculator.
i don’t really like replying to such a long comment with such a short one, but i feel like i need to remind you that the thing that started this chain was
Quick off the top of your head, what’s a third of 9.5mm?
reaching for a string in that situation would be puzzling to me
string would be tough at that scale but weirdly might be easier to make that measurement with than a ruler. just cut your string to 9.5mm length, then divide it by three, one of those divisions is your target length and you even have the other two to check your division’s margin of error against.
to calculate and measure with a ruler would have you measuring 3.16666… which i would not be able to measure with a ruler. now a vernier caliper would be the right tool to make that measurement, and even if mine only had tenths of a millimeter id just round to 3.15mm and mark in between the mm graduations when forced to use that group of tools.
of course that’s if you know how to use a set of calipers. its not as easy as one might think.
lets not forget that your response to the one third of 9.5 conundrum, which was posed by a metric defender, is:
okay then my answer to the hypothetical is 9.5/3, which is every bit as easy to find on any measurement device, or to use for any practical purpose, as 1/24th
which is literally not true as i have explained about the 24th scale ruler and even my digital calipers don’t do repeating digits or express portions of metric measurements in fractions.
of course, in a real world situation i’d never be trying to mark 3.1666…mms because it’s 1/3 of a thou under 1/8 inch. i’d just mark an eighth of an inch like a normal person.
even using a calculator to figure out the length suggests that a person in that conundrum stop using the metric side of their ruler.
the one third of 9.5 conundrum, which was posed by a metric defender
they weren’t a metric defender
which is literally not true
what scenario is there in your mind where you’d need a precision answer to what 1/3 of 9.5mm is, but also not have access to a calculator? and of those scenarios, how many of them would be solved by the knowledge that 1/3 of 1/8 is 1/24? i’m willing to bet the answer is more or less “none”.
and for those that do exist, you can also get drafting rulers that give you 1/3rds of metric measurements.
the accuracy of your equipment isn’t somehow better because you’re dealing with fractions rather than decimal points
you’re right. the person who initially brought up 9.5 was comparing it to the sae equivalent 3/8 (9.525mm, but whos counting).
Just wait for an American to tell you how it’s easier to use fractions with imperial. I’ve legit seen them say shit like 3/8 of an inch is easier to think about than 9.5mm.
the reply was what i was thinking of, the obvious answer: “what if you need to divide by 3?”
so good eye.
one scenario when i’d want a precision answer to 1/3 of 9.5 but also not have immediate access to a calculator is when woodworking. you know, seeing as how 9.5 is (the actual metric defender this time’s approximation of) 3/8… and there’s no way that a calculator would help me there because the result of 9.5/3 is 3.16, a length i’d need at least tenth millimeter vernier calipers to accurately scribe. even 9.525/3 is 3.175, a measurement that requires um precision to scribe!
the inch side of my ruler, however, is graduated in eighths of an inch and i can make that measurement easily with it.
i’ve also used a third measurement of a known diameter when drilling holes in metal to use a technique described in machinerys handbook to cut slots.
you were the one who asked what a third of an eighth was. i’m not sure why. why did you bring up a third of an eighth? was it because you thought it would allow a person to more easily answer the question what is 1/3 of 9.5?
i guess my real question is this:
how does a calculator help you make more accurate measurements?
well, it’s 3.16 mm, not 31.6, but i get your meaning.
in that case if you wanted to be real precise, you’d measure from the left or right side of one graduation to the same side of the next graduation. using that technique a person could get a better 1/8" off a ruler than someone eyeballing fractional mms would.
what kind of cartoon fantasyland do you live in where it’s easier to find a piece of string than it is a calculator?
also, all of this is assuming you have your drafting ruler to hand
do you carry it around with you in your pocket on a day-to-day basis? some deep fucking pockets you’ve got there, although I suppose you already that to the 1/24th inch
my guy, we’re talking about accuracies of millimeters here: you’re not “double checking” your 12" ruler is accurate by slapping your bare carpet gripper up on the drafting table
we no longer live in the pre-industrial age
well, considering i was sitting in the bathroom looking at my phone while wearing clothes when i saw your response, i’d say string and a calculator were both equally close at hand.
only one of those can be used as a measuring tool, though… I guess you could mark off how many calculator lengths something is and measure it later. ngl, i hung a shelf using that technique once, but i wouldn’t use it to find one third of a length. the nice thing about string is that if you don’t have a measuring stick you can always stuff it in your pocket and measure it later when the appropriate tool is at hand.
apologies for any confusion about checking measurements, i wasn’t referring to using my own foot to verify the length of a line, but the common practice of using fractional mathematics to make and verify calculations thousands of years ago and to this very day. we have records of this method being used across language and unit barriers in the ancient world.
there’s another post earlier itt blaming the mars climate orbiter failure on sae unit conversion but nasa puts the blame on itself for not double checking the software and measurements they got back from lockheed. I remember back in the day hearing about that failure on the news and seeing how it was not a problem of difficulty of conversion between the compound units involved, but failure to actually convert between them at all!
since you brought up calculators, there’s a salient point to be made here using a long winded anecdote: when i was in school there was a point in time when suddenly teachers began providing calculators for the exams. this wasn’t that magic moment when the mathematics became just too complicated to expect a middle schooler to do it all on paper. last years class had to use longhand, this years class were provided little blue texas instruments scientific units with a ten digit display and helpful guide to performing logs and other operations that would have been taught using super and subscripts glued to the inside of the cover that would be taken back up at the end of the test.
this didn’t happen going from one grade level to another, but right smack dab in the middle of the academic year. a whole classroom of students yanked bodily into the digital age.
when the parents found out you’d think the questions were gonna be written on the proctors inner thigh. “i had to do it by hand, my kid should too!” “you’re supposed to be teaching them math, not how to use a calculator!” and it’s sister “you’re supposed to be testing their ability to do math, not use a calculator!” but the most common one by far was “they’ll all just get the right answers and we won’t know who studied and learned.”
when the grades came in there was almost no change from last years class.
there were some individual students who did better or worse than their test history would suggest and a whole bunch of new common wrong answers, but by and large aside from errors the ability to perform calculations in response to a prompt was unaffected by ten signed digits of precision.
how could it be that a calculator made no difference?
it turns out that understanding what a question was asking for, verifying ones work and recognizing wrong answers that needed to be rechecked couldn’t be performed by the little blue rectangles.
and many years (and measurements) later i have the same outlook about metrology: comprehension of the goal of a measurement gives you a much better chance to get it right than a calculator.
i don’t really like replying to such a long comment with such a short one, but i feel like i need to remind you that the thing that started this chain was
reaching for a string in that situation would be puzzling to me
string would be tough at that scale but weirdly might be easier to make that measurement with than a ruler. just cut your string to 9.5mm length, then divide it by three, one of those divisions is your target length and you even have the other two to check your division’s margin of error against.
to calculate and measure with a ruler would have you measuring 3.16666… which i would not be able to measure with a ruler. now a vernier caliper would be the right tool to make that measurement, and even if mine only had tenths of a millimeter id just round to 3.15mm and mark in between the mm graduations when forced to use that group of tools.
of course that’s if you know how to use a set of calipers. its not as easy as one might think.
lets not forget that your response to the one third of 9.5 conundrum, which was posed by a metric defender, is:
which is literally not true as i have explained about the 24th scale ruler and even my digital calipers don’t do repeating digits or express portions of metric measurements in fractions.
of course, in a real world situation i’d never be trying to mark 3.1666…mms because it’s 1/3 of a thou under 1/8 inch. i’d just mark an eighth of an inch like a normal person.
even using a calculator to figure out the length suggests that a person in that conundrum stop using the metric side of their ruler.
they weren’t a metric defender
what scenario is there in your mind where you’d need a precision answer to what 1/3 of 9.5mm is, but also not have access to a calculator? and of those scenarios, how many of them would be solved by the knowledge that 1/3 of 1/8 is 1/24? i’m willing to bet the answer is more or less “none”.
and for those that do exist, you can also get drafting rulers that give you 1/3rds of metric measurements.
the accuracy of your equipment isn’t somehow better because you’re dealing with fractions rather than decimal points
you’re right. the person who initially brought up 9.5 was comparing it to the sae equivalent 3/8 (9.525mm, but whos counting).
the reply was what i was thinking of, the obvious answer: “what if you need to divide by 3?”
so good eye.
one scenario when i’d want a precision answer to 1/3 of 9.5 but also not have immediate access to a calculator is when woodworking. you know, seeing as how 9.5 is (the actual metric defender this time’s approximation of) 3/8… and there’s no way that a calculator would help me there because the result of 9.5/3 is 3.16, a length i’d need at least tenth millimeter vernier calipers to accurately scribe. even 9.525/3 is 3.175, a measurement that requires um precision to scribe!
the inch side of my ruler, however, is graduated in eighths of an inch and i can make that measurement easily with it.
i’ve also used a third measurement of a known diameter when drilling holes in metal to use a technique described in machinerys handbook to cut slots.
you were the one who asked what a third of an eighth was. i’m not sure why. why did you bring up a third of an eighth? was it because you thought it would allow a person to more easily answer the question what is 1/3 of 9.5?
i guess my real question is this:
how does a calculator help you make more accurate measurements?
using a ruler to measure a length of 1/8" is as accurate as using a ruler to measure a length of 31mm and eyeballing 2/3 of a mm
the bottleneck at that point is your eyeball and pencil lead, not the unit of measurement
well, it’s 3.16 mm, not 31.6, but i get your meaning.
in that case if you wanted to be real precise, you’d measure from the left or right side of one graduation to the same side of the next graduation. using that technique a person could get a better 1/8" off a ruler than someone eyeballing fractional mms would.
I still don’t see how a calculator helps though.
well yeah, because 1/8" is 3.175mm
1/3 of a mm is a distance between 1/64" and 1/128"
mechanical pencil lead is only about 0.4mm
don’t ask me ask the person who posed the “what’s a third of 9.5mm” question