What Are the Advantages of Base Twelve Over Other Number Bases?

[Bryan Parry]

I am a member of the Dozenal Society of Great Britain ( www.dsgb.orbix.co.uk[/URL] ) . We maintain that base twelve is better than ten, and, in our own small way, try to examine and explore this point.

Anyway, my point is I was wondering if anyone had any interesting thoughts or ideas on comparisons between the main number bases (by 'main', I mean likely to ever be adopted or of potential use i.e. bases 2, 4, 6, 8, 10, 12, 16, 20, 24, 60); any interesting essays on this point; side-by-side comparisons of differing number bases and so forth.

In short, I want this thread to be THE number-bases thread. :biggrin:

 

[chroot]

The drawback of small bases is that numbers have long representations; the drawback of large bases is many symbols to remember.

But it's irrelevant. The choice of base is largely arbitrary, and has no effect whatsoever on the mechanics of arithmetic or higher mathematics. In short, IMO, there's no reason at all to be concerned with it.

- Warren

 

[Bryan Parry]

I disagree

The drawback of small bases is that numbers have long representations; the drawback of large bases is many symbols to remember.

Indeed, hence why I am concerned primarily with comparisons on the octal, decimal and duodecimal/dozenal bases.

But it's irrelevant. The choice of base is largely arbitrary, and has no effect whatsoever on the mechanics of arithmetic or higher mathematics. In short, IMO, there's no reason at all to be concerned with it.

- Warren

I disagree (that it is irrelevant). I do not wish entirely to address your point as this topic will become a debate as to the validity of this topic, as opposed to actually assuming validity and then addressing the topic. However, I will say this much: if patterns in other numbers bases are found (as they have been), which make mathematics more "natural" or maths skills easier to acquire, if the other number bases display certain patterns or properties more overtly, if other number bases make more practically possibly everyday and not so every day tasks, then we must know. It is important we examine other number bases.

I shall therefore start with a basic list of divisions in octal, decimal and dozenal.

Octal
1/2 = 4
1/3 = 2.52 52 52
1/4 = 2

1/5 = 1.4631 4631 4631
1/6 = 1.25 25 25

Decimal
1/2 = 5
1/3 = 3.333
1/4 = 2.5
1/5 = 2

1/6 = 1.666
1/7 = 0.142857 142857 142857
1/8 = 1.125

Dozenal
1/2 = 6
1/3 = 4
1/4 = 3
1/5 = 2.4972 4972 4972
1/6 = 2

1/7 = 1.86A351 86A351 86A351
1/8 = 1.6
1/9 = 1.4
1/A = 1.2497 2497 2497

Note that:

useful fractions (i.e. 1/2, 1/3 and related fractions (1/6, for instance)) are more neatly expressed in dozenal. These fractions are obviously extremely useful in the real world, whether we are talking cutting up cakes to building cabinets.

Dozenal has three fractions running to more than just one number repeated in the decimal parts, as compared to one for both octal and binary.
However, also note that these fractions could be argued of not much use (when is 1/7 of any use?). Furthermore, a fair approximation of 1/5 in dozenal is 0.25, which is far closer to 1/5 than the decimal approximated figure to 1/3 of 0.33 (one-third in itself probably a far more useful fraction, inherently, than one-fifth)

Factors and Prime Factors: octal has two factors, one prime; decimal and two factors, both prime; dozenal has four factors, two prime.

We must also consider that binary multiplication and division is the simplest and most easily attempted form of all; easier than tenery or decimal or any other kind.
We've also to consider that arrangement by six is actually the most efficient method;
That sixty-four - the square of eight- is the first cubic and square number;
That twelve is the first abundant number;
And a host of other things (hopefully this has gotten the ball rolling...)






-Bryan

 

[chroot]

It's still pointless. Sure, it's easier to represent the decimal expansion of 1/3 in "dozenal" than in decimal. Does it matter? No. Anyone with any sense would just call it 1/3 anyway. And when it comes to cutting up cakes or building cabinets, you're going to be limited by how accurately your saw can cut a line, not by how many digits are in your favored expansion of 1/3. Give me a break. If you're so worried about the number of factors in your numerical base, go back to base 60 like the Babylonians.

The only reason to ever worry about numerical bases is when you're building a machine, because the complexity of the switches depends strongly on the numer of positions it must represent.

- Warren

 

[Bryan Parry]

No, I disagree. Again.

What about weights and measures? Basic fractions cannot be expressed in decimal system properly, yet there is an argument for dovetailing numerical base and the W&M system.

Anyway, you still haven't addressed must of my post.

Also, we have already dealt with why base sixty is no good (too many numbers)

 

[chroot]

The expansion of fractions is irrelevant if you keep the numbers as fractions, so your argument is limp.

As far as weights and measures, I know you're going to try to sell us the stupid and cumbersome British system. I, for one, don't care for your proselytizing. Millions of scientists, engineers, and others have already made the decision for you.

- Warren

 

[Bryan Parry]

Your ignorance here demonstrated is supreme. For one, the decision was made for us by bureaucrats, politicians and revolutionaries. Secondly, I am not trying to sell the immensly practical Imperial System to you, I am here trying to discuss number bases. This is a maths board, after all, is it not? And yet you, despite being administrator, seem not to want to discuss a topic of mathematics. I find that incredible.

As to fractions, I see you've not addressed the point. I will with an example:

frequently in metric countries goods are sold in binary or tenery multiples because they are simply more practical (4800mm lengths of wood, binary fractions of 1000g and multiples of 25g).

You see, decimal just doesn't work, as it is incapable of expressing basic fractions properly. Thus, if you are to have a measurement system aligned to base, then the worth of that base being ten is highly doubtful.

Judging from your hostility, I can see that you clearly are one of those hideous metricphiles I hear so much about ( ;) :p ). I would start on practical anthropocentric systems of weights and measures, but this thread is abut number bases. Thank you :)

 

[chroot]

1) The decision is made every single day by countless scientists and engineers around the world. We certainly still have the choice to use the imperial system -- and some companies and some industries still do. No revolutionary figure has ever walked into a university and declared that the metric system is to be used in physics classes for... revolutionary reasons. Certainly I've never heard any political figure order me to talk in terms of kilograms, nor has any warrior ever put a gun to my head and told me to use meters. Engineers and scientists have many choices of unitary systems -- even within the metric system, we have to choose between mks and cgs, for example. We choose units simply because they are the best for the job. If you're going to make the ridiculous claim that somehow the metric system has been forcibly imposed upon me, I'd like for you to support it. Who was this masked man?

2) You're the one who brought up weights and measures (and thus the imperial system), not me. I'm certainly welcome to laugh at is as much as I like, even if you wish I wouldn't.

3) Decimal is capable of expressing any fraction that duodecimal or hexadecimal can express. The difference is largely moot, and it's really ridiculous to spend your time trying to change something as utterly pointless as arithmetic base, particularly in a society where almost all arithmetic (past grade 4) is done by machines anyway. If you really think the convience of being able to express a couple of small-number fractions with whole numbers is so important that we should discard the arithmetic system used by every single culture on the planet for thousands of years to use it, you're out of your goddamn gourd. And I'm proud to say it.

- Warren

 

[Bryan Parry]

1) The decision is made every single day by countless scientists and engineers around the world. We certainly still have the choice to use the imperial system -- and some companies and some industries still do. No revolutionary figure has ever walked into a university and declared that the metric system is to be used in physics classes for... revolutionary reasons. Certainly I've never heard any political figure order me to talk in terms of kilograms, nor has any warrior ever put a gun to my head and told me to use meters. Engineers and scientists have many choices of unitary systems -- even within the metric system, we have to choose between mks and cgs, for example. We choose units simply because they are the best for the job. If you're going to make the ridiculous claim that somehow the metric system has been forcibly imposed upon me, I'd like for you to support it. Who was this masked man?

The decision is made every single day by countless scientists and engineers around the world.

Or not. Metric has almost always been imposed on craftsmen, ordinary people, and engineers. Soem of the most notable actos of imposition were:

*1871 Germany Imperial Decree of Wilhelm I
*1793 France Drastic compulsory law
*1823 French Compulsion reimposed
*Latin america- compulsion in the late 19th Century
*Plus the current business with the 'metric martyrs' in Britain, where traders are prosecuted for using English/Imperial units...

...So people have a choice, do they? Not when the Government(s) compel them otherwise, they don't.


No revolutionary figure... for revolutionary reasons

France. The Terror. They wanted to get rid of all history- they even abolished the Christian calendar and introduced decimal time. Why? Because they hated everything old and wanted a completely new order. For a few years after the revolution, before the calendar was dropped due to its absurdity, years were reckoned in years since the revolution.


As already demonstrated, metric has been forced on the people whether they wanted it or not.

2) You're the one who brought up weights and measures (and thus the imperial system), not me. I'm certainly welcome to laugh at is as much as I like, even if you wish I wouldn't.

What an incredibly intelligent piece of arguing.

I brought Imperial into it, as it is an example of how number bases are relevant. In fact, if we had used a dozenal or binary basis for attaining the metre, the metre would have been 11.7355" (divided into 16 units of a digit size-- binary) or 10.98966" (divided into 12 inch-sized units-- base twelve).
In short, anthropocentric measures were attained.
Likewise, if we say, has 5/8" as the basic size, decimal multiples of this would all be anthropocentric (6.25 " shaftment/hand-width, 62.5" pace, 62,500" mile)

3) Decimal is capable of expressing any fraction that duodecimal or hexadecimal can express. The difference is largely moot, and it's really ridiculous to spend your time trying to change something as utterly pointless as arithmetic base, particularly in a society where almost all arithmetic (past grade 4) is done by machines anyway. If you really think the convience of being able to express a couple of small-number fractions with whole numbers is so important that we should discard the arithmetic system used by every single culture on the planet for thousands of years to use it, you're out of your goddamn gourd. And I'm proud to say it.

- Warren

Who said I was in favour of change? I thought this thread about debating the relative merits- comparing- different number bases. SIlly me.

By the way, many cultures have not used base ten. Some have been sixty, soem have been eight, some have been twenty.

So, back to number bases then...

 

[Zurtex]

The problem with moving to a different base is although more talented mathematicians may be to easily switch it will take a few generations before the confusion finally goes. Furthermore a change base would provide no actual advantage for mathematicians.

 

[Bryan Parry]

Absolutely, the confusions resulting if we did switch would almost certainly be almost insurmountable. However, many mathematicians and philosophers favour/ed the change to base twelve, eight, sixteen sixty-four, four or two (Leibniz, Charles XII, Spencer, Bernard Shaw and a bunch of others)

 

[chroot]

*1871 Germany Imperial Decree of Wilhelm I
*1793 France Drastic compulsory law
*1823 French Compulsion reimposed
*Latin america- compulsion in the late 19th Century
*Plus the current business with the 'metric martyrs' in Britain, where traders are prosecuted for using English/Imperial units...

Do you really think laws that were passed in the 19th century have any bearings on what units scientists and engineers use today? I'll answer for you: no.

France. The Terror. They wanted to get rid of all history- they even abolished the Christian calendar and introduced decimal time. Why? Because they hated everything old and wanted a completely new order. For a few years after the revolution, before the calendar was dropped due to its absurdity, years were reckoned in years since the revolution.

And of course, what happened in France drastically affected everyone on the planet, yes?

I brought Imperial into it, as it is an example of how number bases are relevant. In fact, if we had used a dozenal or binary basis for attaining the metre

How do you use an arithmetic system to attain a unit? That doesn't even make sense. Units are defined by reference standards. The meter used to be defined by some marks on a platinum bar. The meter is now defined with respect to the speed of light and a specific number of wavelengths of a specific atomic emission line.

In short, anthropocentric measures were attained.
Likewise, if we say, has 5/8" as the basic size, decimal multiples of this would all be anthropocentric (6.25 " shaftment/hand-width, 62.5" pace, 62,500" mile)

Binary means base two, not base sixteen. You seem to be keen on anthropocentric measurements -- a philosophy that has been out of date for hundreds of years. Which part of your body would you like to use as a reference for measuring the wavelength of light? How about the distance between galaxies? How big is YOUR forearm?

The metric system does not shine because the kilometer is really a better unit than a mile for people driving their cars. They're comparable, of the same order of magnitude, and certainly equally good. The metric system does not shine because people's heights are much better expressed in kilograms than in pounds -- once again, for the same reasons. The metric system shines in its ability to adapt to anything from picoseconds to nanometers to exabytes without confusing anyone.

Because you're 19 and don't seem to be studying any technical fields, I have to conclude that you've never actually had to do any real engineering or scientific work -- and no, solving a couple of first-year physics problems doesn't count. I really hate to say this, but I feel I must: you almost surely have no idea how much better the metric system is than the imperial system, because your experience with them both is only in your head.

- Warren

 

[chroot]

Who said I was in favour of change?

You linked us to the Dozenal Society of Great Britain, and explained that you are a memeber. The Society's page makes its position very clear:

We want to replace decimal numeration by dozenal.

Now, since you're a member of this organization, I would expect that you adhere to its beliefs. If you do not adhere to its beliefs, why would you be a member?

- Warren

 

[Hurkyl]

Here's a fun fact; there's a nice conversion between powers of two and powers of ten: 2^10 = 10^3 with an error of 2.4%.

There is no such simple conversion between powers of two and powers of twelve; the smallest conversion with similar accuracy is 12^12 = 2^43.

 

[Integral]

I can see 2 valid points for abandoning decimal representation.

.1₁₀= .00011001100... ₂

So if you are doing high precision arithmetic on a computer you MUST round off .1. If you ever find yourself using a counter in .1 steps do NOT ADD .1 to the counter at each step, instead multiply .1 by the step number, this way the round off error will not accumulate.

Base 12 and base 16 (my candidate for a better representation) have more prime divisors then base 10. This means you have more ways evenly of dividing intervals. 10 with only 2 is about as bad as you can get in this respect.

While these may not be extremely critical issues they are valid.

 

[master_coda]

I can see 2 valid points for abandoning decimal representation.

.1₁₀= .00011001100... ₂

So if you are doing high precision arithmetic on a computer you MUST round off .1. If you ever find yourself using a counter in .1 steps do NOT ADD .1 to the counter at each step, instead multiply .1 by the step number, this way the round off error will not accumulate.

Base 12 and base 16 (my candidate for a better representation) have more prime divisors then base 10. This means you have more ways evenly of dividing intervals. 10 with only 2 is about as bad as you can get in this respect.

While these may not be extremely critical issues they are valid.

The only problem with this argument is that switching to a different base doesn't really make the problem go away. If you really need to represent 1/10 on a computer, then the fact that you're now calling it 1/A doesn't help.

And a lot of the floating-point numbers we use on a computer arise from division and not from hard-coded decimal numbers; regardless of what base you're using, you're almost always going to introduce error when you use floating-point numbers for division.

 

[Bryan Parry]

Do you really think laws that were passed in the 19th century have any bearings on what units scientists and engineers use today? I'll answer for you: no.

You are really naive, you know that. Laws passed in the nineteenth century outlawing customary systems of measurement and replacing them with metric of course still have relevance to-day. Look: These customary systems were outlawed and abolished, and all standards switched to metric. It is almost impossible to switch back. That metric is perfectly servicable is why people have not converted back (given the massive effort of converting back), not because other systems are so rubbish there would be no reason to switch back.
Metric is now established in most countries, therefore a change back would be like a change back to speaking Latin- it has nothing to do with Latin somehow being "inferior".

And of course, what happened in France drastically affected everyone on the planet, yes?

Read some history books. But back on topic, of course it affected other nations- when Napoleon invaded half of Europe (a direct result of the Revolution), metric was spread to most of those nations. Likewise, the revolutions in Russia, China and the unification of Germany were the reasons for metrication in those countries. Given that all of the main European nations plus China had converted to metric for these reasons, that means almost the whole world (3/4 of it) would effectively automatically become metric too (due to colonies and spheres of infulence etc). The incredible expense of converting means it is unlikely to ever be reversed.

How do you use an arithmetic system to attain a unit? That doesn't even make sense. Units are defined by reference standards. The meter used to be defined by some marks on a platinum bar. The meter is now defined with respect to the speed of light and a specific number of wavelengths of a specific atomic emission line.

Thank you for intentionally misinterpretting my slightly loose language; YOU HAVE WON THE ARGUMENT, WELL DONE! If you had LISTENED to me, instead of trying to score semantical points and thereby claim victory, when it is obvious what I meant, you would have realized that what I was saying was...

The metre is the size it is as it was intended to be 1/40,000,000 the Earth's circumference. I was making the point that if we has used a binary-type fractio nof the earth, or a dozenal one, we would have ended up with an anthropocentric length unit.

In fact, the base units of Imperial, by the way, excluding the pound, can be expressed EXACTLY in temrs of fundamental phenomona and constants (the foot, second and rankine etc)

Binary means base two, not base sixteen.

I know that. Sometimes 'binary' is used to refer to all powers of two, and you know that.

You seem to be keen on anthropocentric measurements -- a philosophy that has been out of date for hundreds of years.

why is it out-of-date? If a man- be he a tailor, carpenter, bricklayer or man buying his fruit at a market stall- cannot make good approximations in his measuring systems without reference to rulers or standard weights, then the system is rubbish. Anthropocentric measures are better than totally arbitrary units (like the centimetre and metre)

Which part of your body would you like to use as a reference for measuring the wavelength of light? How about the distance between galaxies? How big is YOUR forearm?

Yes, because metric expresses natural constants so nice and evenly, doesn't it? And English/Imperial cannot express large quantities well? Of course it can. For sure, for large things- distances between galaxies- anthropocentric measures are not much better than metric, but most uses of the measuring system are NOT to calculate the distance 'tween galaxies.

The metric system does not shine because the kilometer is really a better unit than a mile for people driving their cars. They're comparable, of the same order of magnitude, and certainly equally good. The metric system does not shine because people's heights are much better expressed in kilograms than in pounds -- once again, for the same reasons. The metric system shines in its ability to adapt to anything from picoseconds to nanometers to exabytes without confusing anyone.

Or not. Prefixes can be used in English too (and are). Microinches, picoseconds, exabytes anybody? (you are claiming seconds and bytes are metric now!?)

Because you're 19 and don't seem to be studying any technical fields, I have to conclude that you've never actually had to do any real engineering or scientific work -- and no, solving a couple of first-year physics problems doesn't count.

Riiiight, insult me. Nice arguing point. Because I am not an engineer, I have no right to debate or discuss matters of metrology or mathematics, right? And because you obviously are involved in it somehow means your views are correct? And the fact I know many engineers who prefer English units too is irrelevant?

I really hate to say this, but I feel I must: you almost surely have no idea how much better the metric system is than the imperial system, because your experience with them both is only in your head.

All in my head!? Are you for real or what?? I sue both systems extensively every day.

 

[Bryan Parry]

You linked us to the Dozenal Society of Great Britain, and explained that you are a memeber. The Society's page makes its position very clear:

We want to replace decimal numeration by dozenal.

Now, since you're a member of this organization, I would expect that you adhere to its beliefs. If you do not adhere to its beliefs, why would you be a member?

- Warren

Warren's world philosophy- It is not possible for a member of an organisation- political or otherwise- to hold slightly different views to those expressed in the organisation's manifesto.

Actually, the DSGB beleives dozenal should replace decimal EVENTUALLY, and in the mean time wishes to conduct research into number bases. That is why I am a member.

 

[Hurkyl]

I think we already have a politics forum, and we have no intention of starting a bickering members forum.

 

[Hurkyl]

Hopefully after the break, if there is a discussion on this topic it can be had.

 

[Integral]

The only problem with this argument is that switching to a different base doesn't really make the problem go away. If you really need to represent 1/10 on a computer, then the fact that you're now calling it 1/A doesn't help.

And a lot of the floating-point numbers we use on a computer arise from division and not from hard-coded decimal numbers; regardless of what base you're using, you're almost always going to introduce error when you use floating-point numbers for division.

I am assuming that the basic step will be .1 regardless of the native base. So if I used a step in a computer algorithm of .1₁₆ this would correspond to a step of 2⁴ or .0001 binary. This is a very nice terminating representation. You can also to this in decimal by taking steps of 1/16 (which I have been known to do).

This leads back to a fundamental flaw with the decimal system when applied to computers. Really the entire concept of making every thing multiples of 10 is not very computer friendly. We would be much better off to stick with and even expand the base 2 nature of the subdivisions of the inch.

As we move into the 21st century we can expect to see computer control become more and more prominent. A 2 based number system would be very nice to have. Octal or Hex would do the job nicely.

Do I believe that it will ever happen? No.

 

[Hurkyl]

Well, the thing is, just what about our interaction with computers would be simplified by the human using an octal or hexadecimal representation?

 

[Bryan Parry]

This is a fair point. Part of the issue here seems to me to be about the possibility that any benefits would be illusory and not real.

 

[Ruthe]

1) The decision is made every single day by countless scientists and engineers around the world.

This is a very pertinent point. Not only was this phrase used here, but in a previous post in this thread by Chroot. This makes my point eloquently.

The metric system was designed by - wait for it - scientists and engineers for - wait again - scientists and engineers. The needs of the working man or woman, the carpenter, the baker, the banker, the housewife, the seamstress, the publican and countless more who far outweighed the number of scientists and engineers, were completely ignored . The prevailing system of weights and measures of the time were bedevilled with a multiplicity of different bases, but these were NOT designed by committee, they evolved from usage based on their usefulness to people that used them day in and day out. It should be pointed out here, before we get any responses regarding the idosyncratic system of weights, measures and money used by the British, that the majority of these began with the Greeks (who are credited as creative and artistic), the Romans (who were very practical and master builders and managers) and Charlemagne (who decreed the monetary system of all western Europe with the livre= 20 sous, and sou = 12 deniers) and used in France up until the metric system was forced into use by legislation. The number base of 12 comes directly from the Romans who did 1727/1728 (artistic license here, not factual but for emphasis) of their calculations with fractions based on twelfths and their sub-multiples.

What is even more important, is that many of these measures did have a common number base, 12. 12 douzieme = 1 line, 12 lines = 1 inch, 12 inches = 1 foot, 12 feet = 1 rod (yes I can substantiate that latter equivalence). There was at one time 12 ounces to the pound which was retained for the Troy pound until that was made illegal.

This usage of 12 was for a very good reason, but one which was of vital assistance to the non-scientist, that of divisibility. The frequency of fractions of 1/2, 1/4 and 1/3 far outweigh the occurrence of 1/5 and the frequency of 1/5 in today's dealings is greatly exaggerated as it is one of only two fractions producing a non-repeating single significant digit decimal in a base 10 system.

The use of a base 10 number system, a place value system, a zero symbol and the decimal point have developed over the last 2-3000 years, each advance improving the usefulness of our calculations. The use of 12 as a base for so many previous weights and measures attest to its value in daily commerce. The move to a duodecimal system of numeration would be just one further step in that process.

However, as is so often demonstrated in the history of science, the entrenched and established view persists in opposing new ideas simply because they strike fear into the hearts and minds of those whose thinking has become so fossilized. Even worse, it threatens to destroy the entrenched view held by the cognoscenti in each of the existing fields of scholarship, reducing their status based on the body of existing accepted knowledge and ones peers in the field.

As is often the case by those who oppose the idea of a base 12 number system, they drag out the chestnut of Imperial measures. What they don't accept, is that those who favour such a system also favour a revision of the system of weights and measures to also be based on a consistent base of 12. Only in this way would a change of any of these things make sense. Number system AND weights and measures.

So, what started as a discussion of base 12 as a replacement for our decimal number system, turned into a discussion of Imperial measures, started I point out by Chroot, not by Bryan. If anybody would like to discuss the merits of different number bases for use in science, technology, engineering, and mundane, daily usage by the general public, fine, let's start a new thread. But let's not muddy the water before we even get started.

PS If this gets me thrown off the forum, then so be it

 

[robert Ihnot]

What bothers me about the British sozenal system, IS THAT'S ABOUT WHAT IT WAS WHEN I WAS IN ENGLAND. They were on the 12 pence to a shilling system.

WE ARE ON THE METRIC SYSTEM and 12 pence to the shilling makes accounting more complicated.

 

[CRGreathouse]

Factors and Prime Factors: octal has two factors, one prime; decimal and two factors, both prime; dozenal has four factors, two prime.

We must also consider that binary multiplication and division is the simplest and most easily attempted form of all; easier than tenery or decimal or any other kind.
We've also to consider that arrangement by six is actually the most efficient method;
That sixty-four - the square of eight- is the first cubic and square number;
That twelve is the first abundant number;
And a host of other things (hopefully this has gotten the ball rolling...)

Base 12 has an easy test for divisibility by 2, 3, 6, and so forth: just look at the last (few) digit(s). Base 10 likewise has an easy test for divisibility by 2, 4, 5, etc. Bases 8 and 16 give only rules for 2, 4, 8, and so on, more restricted than both the preceding.

Base 12 has an easy test for divisibility by 11: sum the digits and test for divisibility by 11. Base 10 has a similar rule for divisibility by 3 and 9. Base 8's rule is for 7. Base 16 gets 3 and 5.

Base 12 has an easy rule for divisibility by 13: sum alternating digits and test for divisibility by 13. (12A -> A - 2 + 1 = 9, so 12A is not divisible by 13.) Base 10's rule is for 11, and base 8 gets 9 (and so also 3). Base 16 gets 17, which is less useful (but overlooked, so maybe good).

Base 1000 (and so base 10 by extension) has a great rule for divisibility by 7, 11, and 13: sum alternating digits (since 11*13*7 = 1001). I don't know of a similar rule for bases 8, 12, or 16 -- but this might be worth exploring.

Base 10 has a good binary conversion: 2^10 ~= 10^3. Hexadecimal has a similar rule, but not quite as nice: 16^5 ~= 10^6. The others don't have anything obvious.

 

[Ruthe]

What bothers me about the British sozenal system, IS THAT'S ABOUT WHAT IT WAS WHEN I WAS IN ENGLAND. They were on the 12 pence to a shilling system.

WE ARE ON THE METRIC SYSTEM and 12 pence to the shilling makes accounting more complicated.

Not in base 12 it isn't and that is what was proposed, not accounting with 12 pence to a shilling in a base 10 number system.

Is it so difficult to understand that the proposed system would have a numeric radix of 12 and a system of weights and measures that use the same radix for ALL magnitudes in the same way the metric and S.I. systems use 10. That the existing system works for the scientific community is NOT in dispute, but it does NOT satisfy the requirements of the general user. The preponderance of 12 as a basis for many non metric measures that evolved from actual use and its applicability to the purposes to which it was applied, is prima facia evidence for the superiority of 12 over 10 as a practical unit.

To put it simply, the non-scientist user likes a simple means to divide things and twelve does it better than 10! If it didn't, the use of 12 as a grouping value would have fallen out of use with the introduction of the Hindu-Arabic decimal place value system.

As for accounting, with a 12 month year, an annual rate is easier to convert to a monthly rate in base 12. Furthermore, even with the existing partially duodecimal subdivision of time, calculation of wages based on halves, quarters, thirds, sixths and even eighths and ninths of and hour, minute or second results in far fewer occasions for rounding due to non-terminating non integer values.

In conclusion, I do not see why the use a base 12 metric system would be such a problem for technologist and scientists. Not only are all the existing facilities of a decimal system duplicated, but they are extended by using a radix of 12. The previously noted greater divisibility is supplemented by a finer graduation in measures and a reduction in the number of digits needed to denote values. There are even more advantages of base 12 vs 10 but this is not the place to present the complete picture.

 

[CRGreathouse]

As for accounting, with a 12 month year, an annual rate is easier to convert to a monthly rate in base 12.

That's not a valid argument, unless you're saying that the cost of converting to a 10-month year is too great.* If you're going to assume that weights and measures will be redone to accommodate base 12, you need to make the same assumption for base 10.

* You don't want to argue this, because the cost of converting other measures to base 12 would be greater than the cost of changing the number of months. You should stick to arguing the long-term benefits of both.

 

[Ruthe]

That's not a valid argument, unless you're saying that the cost of converting to a 10-month year is too great.* If you're going to assume that weights and measures will be redone to accommodate base 12, you need to make the same assumption for base 10.

* You don't want to argue this, because the cost of converting other measures to base 12 would be greater than the cost of changing the number of months. You should stick to arguing the long-term benefits of both.

Not at all. I just don't see the point of changing the calendar to a decimal format. The whole idea of changing to base 12 is to simplify arithmetic. Changing the calendar to decimal just makes things worse. This is not to say I don't underestimate the cost of changing to a base 12 system, or even that it would ever be practical. This is a discussion (or so I thought) on the theoretical benefits of a completely duodecimal basis of numeration, weights and measures, calendar and time. The practical issues are a completely separate topic, but all I ever hear in return is evasion and obfuscation.

 

[CRGreathouse]

Not at all. I just don't see the point of changing the calendar to a decimal format.

A claim was made that base 12 makes working with months easier. Assuming for the sake of argument that this was true, I pointed out that a decimal calendar is easier in a decimal system and that adopting such a calendar would be easier than adopting base 12 everywhere base 10 is now used.

NThis is a discussion (or so I thought) on the theoretical benefits of a completely duodecimal basis of numeration, weights and measures, calendar and time. The practical issues are a completely separate topic, but all I ever hear in return is evasion and obfuscation.

I thought I addressed the benefits of bases 8, 10, 12, and 16 reasonably. But where on this thread are you hearing evasion and obfuscation?

 

[cathalcummins]

As far as conversions between bases go: is there any advantage representing a number as a vector in an n-th dimensional vector space?

So, say I wish to represent the number 73 in base 10, it'd be 73=7\times \vec{v}_1+3\times\vec{v}_0 where \vec{v}_n=10^n, so its representation is on \mathbb{Z}^2 lattice.

The equivalent representation in base 2 is 1001001, so as a vector, it'd be 73=1\times \vec{w}_6+1\times\vec{w}_3+1\times\vec{w}_0 where \vec{w}_n=2^n, so its representation is a point on a \mathbb{Z}^6 lattice.

Is there an obvious relationship between the vector in both spaces? I would be very interested in some feedback!

 

[dodo]

I don't think the vector space paradigm applies. A basis of a vector space is made of independent vectors; while, in your binary example, w_n = 2 w_{n-1}.

Edit: oh, that was possibly a stupid remark of mine. You mean a vector space over the trivial field {0,1}. Then the question is, over which fields you mean, when using a base greater than 2? Since, for non-prime bases, I think, modular arithmetic does not form a field.

 

[cathalcummins]

I don't think the vector space paradigm applies. A basis of a vector space is made of independent vectors; while, in your binary example, w_n = 2 w_{n-1}.

Edit: oh, that was possibly a stupid remark of mine. You mean a vector space over the trivial field {0,1}. Then the question is, over which fields you mean, when using a base greater than 2? Since, for non-prime bases, I think, modular arithmetic does not form a field.

That has cleared the picture up considerably - I was aware of the connection between the "unit vectors" and was more concerned with v_n v_m= v_{n+m} idea.

With regards the underlying field in each case; it seems a little much to use a different field for each conversion and expect it to go smoothly.

Thank you for your response.

 

[zgozvrm]

Just for fun...

Convert the number CAT₃₆ to base 35


What do you get?

 

[HallsofIvy]

Convert the number CAT₃₆ to base 35


What do you get?

Oh, cute! That's the first worthwile thing I have seen in this thread!