Talk:Positional notation

next guy's comment

I think it's odd that the issue of fractional numbers is addressed in the section on base-60 but not in base-10. MFH 13:56, 8 Apr 2005 (UTC)== Fractional numbers ==

Reorganize numeral system stuff

Also, there is really an important job to do consisting in clearly reorganizing all about base-p, decimal, p-adic, notation vs numbering vs numeral system: so many things are said about the same thing more or less correctly and more or less contradictionally in so many different places. MFH 13:56, 8 Apr 2005 (UTC)

Synonym

I added "place-value notation", a term commonly used in U.S. schools, as a synonym for this type of notation. Based on the description I believe this is accurate, but please someone double-check me. Thanks. Deco 01:58, 6 November 2005 (UTC)

Non-standard positional numeral systems

I have addressed certain issues by creating the article Non-standard positional numeral systems, and making related changes to Unary numeral system, Golden ratio base, Quater-imaginary base, Positional notation, Base (mathematics), and Category:Positional numeral systems. Perhaps the reference to the new article in the present article should be in the introduction, as some sort of disambiguation, rather than in the See also section. Apart from that, I suggest further discussion of these issues takes place at talk:Non-standard positional numeral systems.--Niels Ø 14:35, 26 February 2006 (UTC)

Mathematical implications

I removed the following paragraph:

The real value of positional notation turned out to be its ability to invite the further study of numbers. Integers, rational numbers, and place-holders (e.g. zero) were long known about, but irrational numbers, infinity, transfinite numbers, and imaginary numbers were all concepts that could only be discovered once the idea of a continuous number line was implied by positional notation.

The concept of infinity and the invention of transfinite numbers are not related to the representation of numbers as points on a line, but is a purely set theoretic idea. Irrational numbers were found as solutions of geometric problems that had no corresponding numeral (rational) representation, long before positional systems came into use (or at least independent thereof).

Hylas 08:51, 20 March 2006 (UTC)

I, too, found that paragraph somewhat misleading. On the other hand, the notion of the real number line is an important one, and I think it is far more easily grasped if you have a mental concept of number tied to positional notation. Can this be said in the article in a way that is not misleading?--Niels Ø 11:57, 20 March 2006 (UTC)

I added links to the corresponding mathematical ideas. Sadly there is little details provided about the construction. Both articles deal only with the decimal system. Hylas 17:21, 21 March 2006 (UTC)

How is additive system easier for arithmetic?

aside: romans did not commonly use the preceding lower order symbol for substraction. I reckon it would have been more like this: (plus signs aren't needed now that order means nothing) IIII XII = XIIIIII = X IIIII I = X V I = XVI combine, re order, re group sometimes the process would have to be repeated -- I retract the earlier complain about the second paragraph being confused, but I still find it confusing. The problem is that it says additive systems are better for arithmetic, but this doesn't seem right at all. Could this be explained? How does positional notation require memorization of tables? Does this mean multiplication tables? Perhaps this matter should be moved out of the article lead. —Preceding unsigned comment added by 24.55.70.103 (talk • contribs)

I have serious doubts about that statement too. Roman numerals required the memorization of doubling tables (and possibly other multiplication tables) by everyone taking mathematics in school during the first millennium.[1] Without such memorization the student was not considered competent. Positional notation also requires memorization of multiplication tables. Only when a machine is used (like the abacus) are such tables not needed. — Joe Kress 17:17, 2 June 2006 (UTC)

For simple addition and subtraction, the Roman numeral system is basically abacus-like; so for instance

IV + XII = V + XI = VI + X = XVI

This isn't the actual computation someone would perform, but rather an attempt to replicate the abstract process the user of Roman numerals might engage in to perform an addition. For basic monetary transactions, it is slightly faster.

Positional Notation for Base-1

The article linked in the upper right box convers bijective numeration only. There does not appear to be a entry for base-1 positional notation. —Preceding unsigned comment added by 68.46.86.34 (talk) 19:33, 29 May 2009 (UTC)

See also Non-standard positional numeral systems (which confusingly says that unary is such a system despite the fact—also stated—that it's obviously not a positional system) and Talk:Unary numeral system, especially the Non-standard positional numeral systems section. I had forgotten all about this mess, but my viewpoint is the same as yours: there is nothing positional about the unary system. (The reason that true base-1 positional notation doesn't have an article is of course that it would be completely useless, not being capable of denoting a single non-zero number). —JAO • T • C 19:50, 29 May 2009 (UTC)

I don't see how unary isn't a positional system. You could view it as a base 1 system (seems kind of obvious). Its drawback is that it can only represent positive integers. Standard rules for constructing any base_n number work for base 1. 1^0 + 1^1 + 1^2 + 1^3... The position is meaningless, but it's a generalization of positional systems. Aleph Infinity (talk) 00:08, 12 February 2010 (UTC)

I want to add my base converter

What the subject says. It can do fractions (most of the time) to a many places, you can make up a base with whatever characters you want as long as each digit is only a single character, it has a list of common bases to choose from when converting. Plus its GNU GPL. I think mine has more features that the other links in this article. The link to my converter is [2]. I tried to add an old version of this long time ago and some admins got all freaky on me and said that it wasn't allowed b/c you had to pay for something... But I'm trying again. Anyway I made it alot faster than my old one b/c its all client side and only requires javascript. Other than that it had all the same features as before. If somebody hosts it on their site and puts a link in the article to their site, I would like it if you would say on the page that you got it from my website. --Deo Favente (talk) 02:43, 20 January 2010 (UTC)

HA I added it anyways. Now admins, don't be noobish and say you have to pay for it. I'm still confused about all that. In fact, I'm a huge fan of freedom (libre), and with simple web stuff like this free (gratis) generally comes with. --Deo Favente (talk) 05:37, 23 January 2010 (UTC)

I'm sure that nobody wants you to pay to post the website. However, it is generally inappropriate to link to your own website. I looked at the link and your site is rather confusing, you seem to use base not as the numerical base, but as the list of digits. I'm not sure that this site is actually that helpful in it's current form. It would at least help to have some explanation on that page. Cheers, — sligocki (talk) 21:29, 23 January 2010 (UTC)

I have not been able to get this link to work any time that I have checked it, even when modifying the link to be ".com" instead of ".com.". If it's not corrected, it should be removed, as it is completely useless if it cannot be accessed. Aleph Infinity (talk) 00:05, 12 February 2010 (UTC)

Major edit

I did some major rewriting of the article, which apparently wasn't appreciated. Here is the article after I rewrote the section which here is called "Mathematics". First of all, this section is not about mathematics, just some random notes about positional notation that babbles on in different directions and doesn't do a very good job of explaining (in my opinion). If you disagree with my rewrite please let me know what about it bothers you. I'd be happy to make this more of a collaborative work, but I think it needs some major help. Cheers, — sligocki (talk) 01:04, 23 January 2010 (UTC)

I recovered the Babylonian and Greek non-positional forms because both are valid positional systems even though neither is positional within each position. They show that positional systems do not need a large number of symbols equal to their base, as you once stated. The Babylonian base-60 system only used three symbols (ten, one and zero), while the Greek (Hellenistic) system used fifteen (nine letters for units, five letters for tens, and a symbol for zero). The symbols were additive within each position. Not even modern sexagesimal systems use 60 symbols, such as those used for time and angles—they only use ten (0–9) within each position. — Joe Kress (talk) 01:52, 24 January 2010 (UTC)

Time and angles are not positional notations. Time is broken up into some blocks of 60 (but also some of 24, 7, 356.24, ...). In the same way that English weights and measures are not positional systems, even though they are broken up into blocks of 12s, 3s, 4s, 2s, etc. Babylonian numbers do have 60 symbols, they just happen to follow a pattern which can be defined by only 3 symbols and placements. But that is really aside from the point, my understanding of this article is that it covers modern positional notation. To me that means the extension of the way we write decimal to any base.

To be honest I don't know what you mean by positional within each position. Can you explain that? Cheers, — sligocki (talk) 03:26, 24 January 2010 (UTC)

This article is entitled "positional notation", so all aspects of that subject are appropriate, especially its history. I categorically reject your idea that Babylonian sexagesimal positions had 60 symbols. That is your "modern sexagesimal notation" voice talking. By that reasoning, Ptolemy's sexagesimal notation used 60 symbols even though he used Greek numerals that were normally used for all numbers. Unlike Babylonian numbers, Ptolemy only used sexagesimal notation for the fractional portions of his numbers. Those Greek numerals were simply Greek letters with assigned numerical values (e.g., α=1, ε=5, ι=10, τ=300), where numerals above fifty would have been used in the whole number portion, so even they were not new symbols. Even more absurd would be to argue that medieval sexagesimal notation used 60 symbols — that system used decimal numerals that were used for the whole number portions of those numbers. An example is 365 dies 14^I 33^II 9^III 59^IV ... (365.242546219... days) used in the 14th century for the length of the tropical year in the Alfonsine tables. Astronomical numbers usually had a whole decimal number followed by six decimal fractional positions identifed with superscript Roman numerals. The fractional positions were called minutes, seconds, thirds, fourths, fifths and sixths (in Latin). The first two superscript Roman numerals have now degraded to simple marks, ′ and ″. If hours or degrees were the whole number, its fractional sexagesimal positions were still called minutes, seconds, thirds, fourths, etc. By the 19th century, thirds, fourths, etc. were replaced by decimal fractions of the seconds sexagesimal position.

I said Babylonian and Greek sexagesimal numbers were not positional within each position, because both were additive within each position. Thus a Babylonian sexagesimal position like <<<|| meant 10+10+10+1+1=32. The corresponding Greek sexagesimal position λβ meant 30+2=32. But the corresponding medieval sexagesmal position was positional because it was the ordinary decimal number 32. Elsewhere, medieval numbers still used Roman numerals. — Joe Kress (talk) 01:43, 26 January 2010 (UTC)