## How to pronounce numbers in English?

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Carolus Raeticus
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### How to pronounce numbers in English?

Hello!

I have a question entirely unrelated to Latin/Greek. I'm regularly reading about astronomy, and every time I encounter certain numbers, I am wondering how to properly express them in English. Can anyone help me and spell them out for me? It's been bothering me for ages not knowing how to pronounce such numbers.

Examples for numbers (scientific notation):
• 1.5 x 10^-2 W/kg
• 2 x 10^3 W/kg
• 4 x 10^26 W
• 2 x 10^-12 kg/m³
Examples for equations:
• F = (G * m1 * m2) / r²
• a = v²/r
• v = sqrt((G * M) / r)
• M = (r * v²) / G
Thank you,

Carolus Raeticus

PS: I've just (the day before yesterday) received my copy of the 4th edition-"Oxford Classical Dictionary". It looks great (and due to its bulk serves as a great weapon against potential burglars).
Sperate miseri, cavete felices.

Sceptra Tenens
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### Re: How to pronounce numbers in English?

So far as I know, we usually don't pronounce them at all - we refer to the equation as a whole. E.g., "Einstein's equation" for E=mc², Newton's law of universal gravitation for F = G((m1*m2) / r²). Given the fact that equations are often case sensitive, there is no good way to convey all the data verbally.

If I were to attempt to read those out loud, though, I would probably do it like this:

1.5 x 10^-2 W/kg - "One point five times ten to the negative second power Watts per kilogram"
2 x 10^3 W/kg - "Two times ten to the third power Watts per kilogram"
4 x 10^26 W - "Four times ten to the twenty-sixth power Watts"
2 x 10^-12 kg/m³ - "Two times ten to the negative twelfth power kilograms per cubic meter"

Those are the easy ones - no data is lost in reading aloud. The next ones are trickier.

F = G((m1*m2)/ r²) - For this one we have to expand the equation to minimize data loss:

F = G * m1/r² * m2/r² - "F = G times M-one over R squared times M-two over R squared" - this is slightly ambiguous, but the best I can do. If I were telling this equation to someone, I would just make sure that he knows that the second fraction is not in the denominator of the first.

a = v²/r - "A equals V squared over R"

v = sqrt((G * M) / r) - Is "sqrt" "square root", or a string of variables? If "square root", I would have just put it as ^0.5 (to the power of one half) to avoid ambiguity.

Anyway, if it's square root: "V equals the square root of G over R times M over R" - this is also ambiguous.

M = (r * v²) / G - "M equals R over G times V squared over G"

[quote]PS: I've just (the day before yesterday) received my copy of the 4th edition-"Oxford Classical Dictionary". It looks great (and due to its bulk serves as a great weapon against potential burglars).[quote]

If you ever need someone to keep an eye on it for you, I'm your man.
mihi iussa capessere fas est

Carolus Raeticus
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### Re: How to pronounce numbers in English?

Salve!
Sceptra Tenens wrote:So far as I know, we usually don't pronounce them at all - we refer to the equation as a whole.
Really? That's interesting. Somehow, to me numbers/equations are somehow less "real" if I can't pronounce them (I'm not the visual type). So I find reading English texts using such numbers or equations a trifle frustrating. Unable to pronounce them properly in English I find myself shifting back to German, and that prevents proper immersion in the text/language.

Bye,

Carolus Raeticus
Sperate miseri, cavete felices.

mingshey
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### Re: How to pronounce numbers in English?

F = G * m1/r² * m2/r² - "F = G times M-one over R squared times M-two over R squared"
v = sqrt((G * M) / r) - V equals the square root of G over R times M over R
This way you would put R to the fourth power and R squared, respectively, in the denominator, instead of R squared and R, respectively.

You might just read them as it's put in the equations, without any serious loss of data, if put along with the written equation.

F = G * m1 * m2/r² - ef equals gee times em sub one times em sub two over r squared

v = sqrt((G * M) / r) - vee equals squared root of gee times em over r

If you have to dictate them by way of a telephone, you could insert "open parenthesis" and "close parenthesis" appropriately.

Sinister Petrus
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### Re: How to pronounce numbers in English?

mingshey wrote: F = G * m1 * m2/r² - ef equals gee times em sub one times em sub two over r squared
In some cases you don't even need to say "times".

PE = mgh

pee ee equals em gee aitch

KE = 1/2 mv^2

kay ee equals half em vee squared

And for complex units, never say times.

3.4 x 10^6 N•m

three point four times ten to the sixth Newton meters (Never ever Newtons per meter [obviously] or Newton times meters)

5.9 x 10^-34 kCal

five point nine times ten to the negative thirty fourth kilocalories