# Pronunciation of Decimal Units - How do you say these in English?

L

#### LabManZulu - 2004

Well... my first time, my first post on this board....wich BTW i aplause the team that created this forum... GOOD work!

Now for my question... i just started a new position in a calibration lab... my previous experience in metrology was all in french... now that i'm working in english environment, i have a certain dificulty calling certain numbers...please help!

How do you pronounce this:

.1
.01
.001
.0001
.00001
.000001
.0000001

#### Wes Bucey

Moderator
Welcome to the Cove! Good question.
Here's a chart that might help.

Sorry, I'm too busy to convert this to use within the text box, but I want you to have the answer so I'm just attaching a word doc with the chart.
Note Americans and folks using British English have a different concept of the nomenclature for quantities larger than millions.

I'm not sure I understand the reasoning most people have for using the prefix instead of the billionths, trillionths, etc.
I find most of MY audiences are not sure of the exact meaning of "nanosecond" versus "picosecond," so I usually explain
each time I introduce a new term. It certainly is a great shortcut to say "nanometer" instead of "one-billionth of a meter" or to verbalize scientific notation like "10 to the minus sixth meters" for 0.000001.

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#### LabManZulu - 2004

Wow that was fast!!! Thanks Wes for the chart!

So....Let me see if i get this right....

.1 = tenth
.01 = hundredth
.001 = thousandth
.0001 = ?
.00001 = ?
.000001 = ?
.0000001 = millionth

In the case of the "millionth", do you use "micron" in the States?
How about the three that are missing. Any particular nomenclature ?

#### Wes Bucey

Moderator
.1 = tenth
.01 = hundredth
.001 = thousandth
.0001 = ten thousandth
.00001 = hundred thousandth
.000001 = millionth
.0000001 = ten millionth
Re: "micron"
From: http://www.unc.edu/~rowlett/units/dictM.html
micron (µ) [1]
a metric unit of distance equal to one millionth of a meter. "Micron" is simply a shorter name for the micrometer. In 1968 the CGPM decided to drop the micron as an approved unit and recommend that micrometers be used instead. Microns, however, are still in common use.
micron (µ) [2]
an informal unit of pressure widely used in vacuum technology. In this use, a micron is a micron of mercury, that is, 0.001 mm Hg or approximately 1.333 microbars (µbar or µb) or 133.3 millipascals (mPa). For all practical purposes, 1 micron is identical to 1 millitorr (mTorr).

Summary:
As each decimal place is added, the value is changed by the power of ten. Therefore, the progression (in American English) is
1. tens
2. hundreds
3. thousands
4. next step in nomenclature (example - "millions" or "millionths," depending which side of the decimal point)
Then the progression begins again:
1. ten millionths
2. hundred millionths
3. billionths (American) or thousand millionths (British)

#### Tim Folkerts

Super Moderator
LabManZulu said:
.1 = tenth
.01 = hundredth
.001 = thousandth
.0001 = ?
.00001 = ?
.000001 = ?
.0000001 = millionth
Of course, most people just say
"point one"
"point oh one"
"point oh oh one"

In the case of the "millionth", do you use "micron" in the States?
For metric lengths, yes. For other units, no. The problem, of course, is that "micrometer" could be MIC ro meter = 0.000001 meters or mi CROM eter = a measuring instrument.

I'm not sure I understand the reasoning most people have for using the prefix instead of the billionths, trillionths, etc.
I imagine the main reason prefixes are used is that they are the "standard" international metric notation. Whether you are in US or UK or France or Japan, "12 nm" is universally understood as 0.000000012 m.

One other minor note. You need to be a little careful with "ten thousandths". Depending on context, it could mean 1/(ten thousand) or 10 x 1/(one thousand).

Tim F

#### Wes Bucey

Moderator
Tim Folkerts said:
Of course, most people just say
"point one"
"point oh one"
"point oh oh one"
We need the smiley with a halo over it for "holier than thou" guys like you, Tim.

Truth be told, no one listens to us Quality grunts - the suits just want it in writing with numbers and make sure you put a place holder zero in front of the decimal point or some nasty person will rap your knuckles with a straight edge.

Tim Folkerts said:
I imagine the main reason prefixes are used is that they are the "standard" international metric notation. Whether you are in US or UK or France or Japan, "12 nm" is universally understood as 0.000000012 m.
Right! Because then everyone is talking metric, not burdened with English system of weights and measures (inch-pound system.)

Tim Folkerts said:
The problem, of course, is that "micrometer" could be MIC ro meter = 0.000001 meters or mi CROM eter = a measuring instrument.

One other minor note. You need to be a little careful with "ten thousandths". Depending on context, it could mean 1/(ten thousand) or 10 x 1/(one thousand).
Boy, this is absolutely true. Of course, I have heard folks who speak English as a second or third language pronounce the word "micrometer" so many ways, I almost always have to ask which they mean because they unconciously think "if it's spelled the same, it must be pronounced the same" so they use the same pronunciation no matter which they are referring to.

I find myself distinguishing the difference by using the terms
"one ten-thousandth of an [unit]"
OR
"ten one-thousandths of an [unit]"

#### Raffy

##### Quite Involved in Discussions
Hello LabManZulu,
Okay Let me try:
.1 = tenth
.01 = hundredth
.001 = thousandth
.0001 = ten-thousandth
.00001 = hundred-thousandth
.000001 = millionth
.0000001 = ten-millionth
Welcome to the Cove!
Best regards,
Raffy

#### apestate

##### Quite Involved in Discussions
thousandths and millionths

just because I love sounding this out, I'm going to do it too, but with a twist. I will tell you how these inch increments are said in a shop.

.1 = one hundred thousandths
.01 = ten thousandths
.001 = one thousandth
.0001 = tenth

see how goofy that is? it does make things easier though when discussing units. it seems to me that english manufacturing / metrology jargon goes in two bites. the .001" set, and the millionths set.

up to .0001" is spoken of in terms of the .001" increment. .0001" is now called a tenth, .0005 a half, because we're thinking in terms of thousandths of an inch.

.00001 = ten millionths
.000001 = ONE MILLIONTH!!

This is why nobody seems to say "one hundred millionths." they would be talking about 1/10 of 1/1000!

it's tricky because one person could say "one hundred thousandths of an inch" two ways. he can mean .1 or .00001 literally.

however, it is much more common to speak of the increments using the two currencies of thousandth and millionth.

welcome to the cove~!

#### Wes Bucey

Moderator
Let's be fair, atetsade. Just because "the guys in the shop" say it, doesn't make it acceptable in "Quality speak."

I venture to say that if I walked into any shop in America (and I've been in quite a few), everyone would understand me when I say,
"The tolerance on this dimension is plus or minus five ten-thousandths of an inch."
Whereas, if I said,
"The tolerance on this dimension is plus or minus five tenths."
There would be lots of opportunity for confusion or error in many of those same shops.

#### cncmarine

##### Quite Involved in Discussions
In the manfacturing world the average employee would understand the second quote. (.0005 = five tenths)Its not right but its true.