According to one of the questions already asked on EL&U, “E = mc²” is read as
E equals M C squared.
How do we read “E = (mc)²” so that it is not mistaken for “E = mc²”?
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As a member of the mathematics community for many years, I'd say the standard pronunciation is:
E equals the quantity MC squared
Also, as pointed out by Mark Adler in the comments, this is the standard pronunciation used when recording mathematics textbooks for the blind (thanks for the info Mark!).
Trying to swap things around to make it the least ambiguous possible and still sound light:
E equals the square of MC
The word all can be used to indicate the grouping that is shown in print by brackets, so this could be read as
E equals M C all squared
In this specific example that’s probably sufficient for a listener to realise you’re saying something different from the more common “E equals M C squared”, and the correct meaning ought to be clear because it’s a simple expression with no other plausible interpretation – but in the general case it can be extremely difficult to express the precise meaning of an arbitrarily complex equation using a natural language in place of a symbolic one.
As a mathematician, I would say "E equals m c quantity squared".
Why does the mathematical notation system exist? It exists because it is an easier way to explain mathematical expressions. Spoken languages have limits. They are not able to perfectly transfer every idea from one person to another, and they are not fully capable of describe feelings and emotions. Don't expect much from spoken language. Don't expect to easily speak everything you want to say. Peoples inner feelings and what they are trying to say usually has a wider meaning then they actually say.
Your question is just an example of the limits of spoken languages. Complex mathematical expressions can not be easily expressed with spoken language. If you want to say them, you need to form long sentences.
For example, A = ((a2b3)2 + 5 - ab2 - (ab)2)3 can be read as "capital A equals, open parenthesis, open parenthesis, a squared times b cube, close parenthesis, square, plus five, minus a times square of b, minus, open parenthesis, a times b, close parenthesis, squared, closed parenthesis, cube".
Talking about mathematical expressions requires a lot of words. Look at this very common dialog below (science students usually explain it this way):
A: ... He completed his homework after reaching the formula "E equals m, c squared".
B: I know it. That famous formula which Einstein found, isn't it?
A: No, this one is different. You take square of both m and c in this one.
B: Oh, I understand.
There is no standard for reading mathematical expressions. Because it is very hard to set a standard for it since the complexity of expressions have no upper bound. In practice, the reader reads the expression without putting any extra afford in it for making it clear (even usually skips the inner parenthesis, etc for simplicity - if he/she reads every detail it becomes a bother for both the reader and listener). Listener knows the subject and recalls the expression in his/her mind as he/she listens to. If the listener cannot remember it, he asks the reader for its details. If it is a conference, the speaker must use a projector, white board, or any other tool for clearly showing the mathematical expression (if he doesn't use any explicit tool and just speak it, then it means that that conference is not well organized; people usually complain after a conference like that).
You should take a pencil and paper with you when you are talking about something related to mathematics. Without using a pencil and paper, you cannot explain the derivation of a mathematical formula to your friend as easily as talking about the summary of a novel or debating about a political matter. This is because, as I stated above, spoken languages are not convenient for expressing mathematical expressions.
Of course, it is easier to read simpler expressions. For the case of E = (mc)2, you can simply read as "E equals the quantity MC squared" as @Macro suggested.
Due to the distributive property of exponentiation over multiplication, you could read this as "E equals M squared C squared", also written E = m²c².
Apparently I'm the odd one out:
E equals paren M C close-paren squared
I had a stats professor who drilled into my head the formula for variance:
E[x^2] - E[x]^2
"E xsquared minus E x ... squared"
With a longer pause every time he said it. It may not work in all circumstances, but I found it to be a clear (and memorable) way of saying the formula aloud. So, for your question,I think it would be valid (at least to mathematically inclined listeners) to say:
"E equals m c ... squared"
"E equals square of the product of M and C"
If your audience can physically see you, you could use a hand gesture while speaking:
"E equals" [use both hands to draw parentheses in the air] "mc" [finish gesture, slight pause] "squared".
E=mc^2 is common everyone assumes the first version:
E=mc^2should be conveyed as
E equals m, c-squared.
E=(mc)^2is conveyed as
E equals m,c whole squared.
It really comes down to the pause. Consider this,
When you say
x plus (pause) y over z it means
x plus y (pause) over z implies
Edit: frankly I don't understand the use of quantity. But, that's just me.
E = mc² is pronounced as E equals M, C-squared. With slightly different rhythm, E = (mc)² can be pronounced as E equals (MC)-squared.
E equals mc whole squared.
This is the notation used in schools and Universities usually.
Generally, I'd differentiate between
xy² by saying for each:
(xy)² - "x y squared"
xy² - "x times y squared"
However, if you're concerned with the specific case of
E = mc² this won't work since the accepted pronunciation of the familiar equation doesn't follow these rules.
E equals the squared product of m and c.
Read it as
E is Equal to MC the Whole Square
Reorder by decreasing exponent and pronounce that way:
E equals c squared m
E equals c squared m squared
If only Einstein had thought to write it that way originally, sigh.
I think "all" is still the easiest way to express that equation "e equals m,c all squared". This is meaningful to non mathmaticians too (unlike quantity or perhaps even product). Pauses are unsafe (especially on the phone etc). Order changes can work but can also confuse (e.g. "e = the square of mc").
For example - the famous quadratic factorisation equation (-b+/=SQR(b^2 - 4ac))/2a "minus b, plus or minus, the square root of b squared minus four a c, all over two a"
The real answer is, it depends on your audience - use the language graded to the least proficient listener (that you expect to understand - not the baby or dog).
The most unambiguous way to say this, if a little awkward, would be:
E equals the square of the product of M and C.
(E)nergy is equal(=) (Mass of the Object(m) multiplied by the Speed Of Light(c)) Squared(²)
One would obey the order of operations and perform the multiplication inside the
() parenthesis, then square the result.
The pronunciation would be said as
Energy is calculated by multiplying the speed of light by the mass of the object and squaring the result
It will be read as E equals to whole of mc square.
What about this.
E equals MC in brackets squared.
The "open/close" parentheses sounds good. One simplistic option when pronouncing the statement would be to say M-C very quickly as if they were one.
I'd speak in pseudo-polish notation:
E is equal to the square of the product of M and C.
I’d just say
E equals mc whole square/squared.
How about E equals m squared times c squared?
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