Personally I use a leading zero to add clarity, but accepting there are other standards I don't obsess.

I don't think I could handle $1,000,00 as $1,000.00. They have two different connotations.

Why would you need to handle $1,000,00 as anything? I'm not aware of any convention that uses the same punctuation mark for both a digits separator AND a radix mark.

What is most confusing (in both directions) is when you have a number such as

x = 12,345

I see that and see something between twelve thousand and thirteen thousand. In other parts of the world, they see that as something between twelve and thirteen.

Usually, there is enough context (or at least one number somewhere, such as y=12,5) to clue you in to what convention is at play.

This is why the formal style recommendation is to NOT use any punctuation for digit separators and, instead use a space. That way you know that ANY symbol between digits is a radix point. So you would have

$1 000.00

or

$1 000,00

I definitely prefer the leading zero, particularly in handwritten stuff or stuff that is likely to be printed out and used for some time (and subject to dirt and scuffs and such).

That is why the convention started of using the prefix as a radix point so that 4.7kΩ was written as 4k7, while 0.47kΩ was written as k47 and 47kΩ was written as 47k. If there was no prefix, then R was used instead (and C for a capacitor and L for an inductor).

 

Look at a lot of checks? It is pretty much a financial standard. I didn't create it, but I like getting commas in checks myself, though it is rare enough.

$1,245.34 works for me.

Personally I don't think .50342 violates any standards, though like I said, I don't do it myself.

Standards are funny things, they exist because they were accepted a long time ago, and logic does not always apply.

 

According to the conversation, it appears that the answer is, "because elementary school teachers are not (scientists or engineers)".

http://mathforum.org/library/drmath/view/52352.html

 

Look at a lot of checks? It is pretty much a financial standard. I didn't create it, but I like getting commas in checks myself, though it is rare enough.

I don't think I have ever seen a check that used a comma both to separate groups of digits (i.e., thousands separator) AND used a comma as the radix point.

 

I don't think I have ever seen a check that used a comma both to separate groups of digits (i.e., thousands separator) AND used a comma as the radix point.

Right enough, but the rest of the digits on the check stub do, I just looked at an old check.

 

Right enough, but the rest of the digits on the check stub do, I just looked at an old check.

The rest of the digits do what? Use a comma for both the thousands separate AND the decimal point? I'd love to see a scan of that check stub.

Frankly, I thought you had just made a typo in the post where you said that you didn't know if you could handle $1,000,00 instead of $1,000.00 but apparently that's not the case. I'm still pretty sure that I have never seen anything like this in any context whatsoever.

 

I think I'll pass on sharing my personal data. You can believe me or not, I don't really care. I did take the time to verify, which is good enough for most folk.

It is an old enough standard, it was old when I was new.

 

Back in the 1950’s, and before keyboards, the decimal point was placed at the centre of the number and not at the foot. That gave it its own column and was difficult to miss.

 

Here, numbers writen in checks are always as this: $154.320,76 (Hundred fifty four thousands three hundred twenty pesos with seventy six cents.

As far as I know, decimal separator is taught and expected to be used when writing figures to express a quantity (with the additional benefit, to me) that makes them much easier to read.

In my personal case, when they are used to identify an item of a series of something (steel coils, a frequent case) I separate them in groups what makes easier to read; something like this "24 88 124A". Excel will put them in order with no trouble.

Edit to add:

Forgot to say that here, the use of the leading zero as in 0,34 or 0,32876, (values less than 1) is taught and required.

What I believe led to the usage of that "point forty seven" mentioned in my previous post is that calculators, besides bringing no comma but point to precede the decimal part, they do not require to press the 0 before the point".

 

I can testify that, clear back to the 1950's the leading zero was not taught in American schools. That doesn't say anything about, "why", only the fact that it has been accepted practice for nearly 60 years.

I was a young nerd. I would have remembered.

Being a child of the 1950s too, that was the case until I got to high school. At that time I knew I wanted to be a machinist, and was lucky enough to go to a school that taught many types of trades. Not a "trade school" though.

The first thing they taught us was that in machining blueprints the decimal point was always preceded by a number. Even if it was a Zero. To this day I still do it this way with "measurements".

 

can someone explain to me why the uk/us custom is to write numbers as .5 instead of 0.5?

I'm British, and I very rarely see the leading zero omitted. We were always taught to include it (I agree that writing .5 could easily be mistaken for 5 with bad eyes / bad printing). Maybe it's an old fashioned habit, thankfully dying out? We were also taught not to use a comma when writing long numbers (1,000,000 yuk!).

Capacitor notiation is easy to explain, however. In America, the "nano" has never really caught on. They have always preferred to use picofarads or microfarads, but turn their noses up at the nano in between, so you see a lot of annoying values like 0.1uF on American schematics!

But what I really HATE is the continental habit of using a comma instead of a decimal point. A comma is a punctuation mark, not a mathematical symbol! Grrr!

What I DO like is the American habit of using a colon to separate hours and minutes (12:57) instead of the British/Euro dot (12.57). A colon makes it really easy to see that you're talking about time and not just any old number.

 

But what I really HATE is the continental habit of using a comma instead of a decimal point. A comma is a punctuation mark, not a mathematical symbol! Grrr!

The symbol (ASCII 046) is also used by you as a punctuation mark.

Period

 

I think I'll pass on sharing my personal data. You can believe me or not, I don't really care. I did take the time to verify, which is good enough for most folk.

It is an old enough standard, it was old when I was new.

Oh, I definitely understand not wanting to share your personal data, though there is such a thing as redacting everything except the pertinent info. And it's certainly also fine if you don't care that I'm not going to believe that it is a financial standard to use commas for both the thousand separator and the decimal point in the same number without seeing proof.

 

I always thought it was a correct notation (at least in the metric system) to always use a 0 before the decimal point.

I was in schooling during the time Australia changed from imperial to metric, and they made a point(!) about correct use of the decimal point. And of course the decimla point is used a lot more in a modern metric system than in the obsolete imperial system; 1/8 = 0.125

Here's an interesting quote from a math forum;
"First, in writing drug prescriptions:

Good Prescribing Guidelines (Westmead Hospital Department of
Pharmacy - Khai Bui)
http://www.westmead.nsw.gov.au/alliedh/pharm/pages/goodpres.htm

"Never leave a decimal point naked, such as .5 mL. When the decimal
point is not seen, a tenfold overdose may occur.

"When a decimal fraction must be prescribed, always write a zero
before the decimal point.

"Never put a decimal point and zero after a whole number such as
2.0 mg. This should be written as 2 mg. If the decimal point is not
seen, a tenfold overdose may result."

Again,

Medicine, Malpractice and the Law (a paper by Raymond Wacks)
http://www.medicine.org.hk/bma/programme.htm

"The expression of drug dose and units should be clear. For whole
numbers it is better to avoid following with a decimal point and a
zero which may be misinterpreted as ten or one hundred times the
appropriate dose. For numbers less than one it is essential to
place a zero before the decimal point."

Similarly, in product labels:

FDA Guidelines (U.S. Government FDA/ORA Compliance Policy Guides)
http://www.fda.gov/ora/compliance_ref/cpg/cpggenl/cpg140-500.html

"A zero before the decimal point should be used in numbers between
1 and -1 to prevent the possibility that a faint decimal point will
be overlooked.

"Example: The oral expression "point seven five" is written 0.75."

Next, in the metric system:

Metrics the Right Way (George Sudikatus, ICF KH Metric Coordinator,
Pacific Northwest National Laboratory)
http://www.pnl.gov/ag/usage/metrics.html

"In the United States, the standard decimal marker is a dot on the
line (i.e., a period or 'decimal point'). When writing numbers less
than one, add a zero before the decimal marker. For example, on a
drawing you might define a small length in English units as
.032 in., but write the metric length as 0.81 mm."

Also, some publishers and organizations include it as part of their
style guides:

Instructions for Authors (Publisher: Taylor and Francis Group)
http://www.tandf.co.uk/journals/authors/t-authors/wstauth.html

"Use a zero before the decimal point for numbers less than one. For
example:

t = 0.40

"However, do not use a zero before the decimal point when the
number cannot be greater than one. This occurs with correlations,
proportions and levels of statistical significance. For example:

r = .27, p < .01

On the other hand (!):

Preparing Manuscripts for Demography (Department of Demography,
Georgetown University)
http://www.georgetown.edu/departments/demography/main/Student/demo.htm

"Decimal fractions should not include a zero before the decimal
point (e.g., .05 is correct; 0.05 is incorrect)."

These are not carefully chosen references, just those that I found in
a quick search. They should suggest that inclusion of the zero is a
common, though perhaps not universal, practice, and has good reasons
behind it. Therefore, I think it is appropriate for students to become
familiar with this style. We can let them become lazy later - if they
don't become pharmacists.

On the other hand, I don't think I would require them to always put in
the zero themselves; and I would make sure they saw numbers written
without the leading zero to make sure they knew it meant the same
thing.

- Doctor Peterson, The Math Forum
http://mathforum.org/dr.math/ "

I noted above they talk about the oral expression "point seven five", interesting, I was taught to say "zero point seven five" or "zero point five".

 

In the daysI of radio comms, clarity dictated the spoken language. 0.5 was zero, symbol for decimal point, five.

Leading zeros are required for clarity. In the homework section, I would use leading zeroes before the decimal. Here it's more forgiving if you don't unless There is unclarity.

 

Yes and many states are also not teaching cursive writing anymore. But back to the original question, how would you like to send out for a 1/2" dia.(0.5) shaft and get a 5" one instead due to where the print was folded.

 

Actually not an answer to your question; locally, people working in electronics name a cap like that as "point forty seven".

In the lists that people bring when buying on the counter, it seems common practice to write the values as you say, .33 , .47, .68.

Reminds me of bullet sizes for guns: forty-five for 0.45 in.

 

Reminds me of bullet sizes for guns: forty-five for 0.45 in.

Oddly enough, and American enough, I've never seen anyone put a leading zero on a .45 cal.

http://en.wikipedia.org/wiki/.45_ACP

 

Reminds me of bullet sizes for guns: forty-five for 0.45 in.

In bullet sizes (in inches), not only is the leading zero almost always left off, but the decimal point is also frequently left off as well. This causes few, if any, problems because a pretty safe assumption, for practical purposes, is that the diameter is always between 0.1" and 1.0". So talking about a 45 and a 357 and a 460 caliber is understood to be 0.45", 0.357", and 0.460" (and keeping in mind that the caliber is nominal -- truly, "by name" -- and not always the actual dimension).

The one that threw me for a long time was the designation of the Mark 7 gun as a 16"/50 caliber. At first, I thought it meant that the diameter was 16.050". But no, in artillery and such, the term "caliber" gives the length of the gun barrel (tube) as a multiple of the bore diameter. So the nominal length of the Mark 7 tubes was 800" (66' 8") (the actual length was 816").

 

According to the conversation, it appears that the answer is, "because elementary school teachers are not (scientists or engineers)".

http://mathforum.org/library/drmath/view/52352.html

Very interesting commentary.