# How to read/spell/pronounce/say math or physical calculus in English?

1. Oct 16, 2007

### PseudoTensor

Hello all

I am nearing my graduation (physics) and consider myself fluent in general English. Although I had to dig through many books in English during the study I never actually had to verbally comunicate with another person about physics/maths calculus. After a chilling finding how poor in this aspect I am, I decided to ask for some help. So, can anyone please tell me some basics, or how to read next four examples:

http://shrani.si/f/q/jn/3YaIzBfr/mathphysics.jpg [Broken]

I am more interested in the "quick" version (if there is one), which is to be used in the middle of the sentence, rather than a description.

I'd like to encourage anyone else whose native language is not English to post examples here.

Thanks in advance and appologies if this is not the appropriate forum.

Brgds, PT

Last edited by a moderator: May 3, 2017
2. Oct 16, 2007

### CRGreathouse

"Eight point two three times ten to the neg thirty-five" or even "Eight point two three e minus thirty five"

"del a del b" and either "derivative of a (with respect to b)" or more often just "dee a dee b"

"pi squared over the fifth root of ninety"

"h-bar" is always the name for the first; the second would probably be called "lambda-bar" in like fashion. (lambda = LAM-duh, silent b in English)

3. Oct 16, 2007

### Math Jeans

Actually, that would be "partial a partial b". Del implies a gradient, not a partial derivative.

4. Oct 16, 2007

### CRGreathouse

You say it how you say it, and I'll say it how I say it. I've heard "partial a partial b" but only very rarely. I more often hear "nabla a nabla b" than "partial a partial b". In fact, come to think of it, I've even heard "dee a dee b" for the partial derivative of a w.r.t. b -- and not that infrequently.

5. Oct 17, 2007

### cristo

Staff Emeritus
You mean "pi to the 6 over..."

I would say "dee a, dee b". However, I agree with the other poster: I've only ever heard "del" to mean "gradient."

6. Oct 17, 2007

### J77

As a born and bred English speaking scientist, I'd say...

1. eight point two three times ten to the minus thirty five.

2. dee aye by dee bee (for both -- or possibly: partial dee aye by dee bee, for the 1st).

3. pi to the six over the fifth root of ninety.

4. aich bar or lamdba bar.

7. Oct 17, 2007

### PseudoTensor

Thanks a lot gentlemen, much appreciated!

8. Oct 17, 2007

### HallsofIvy

You can say whatever you like but you'd be wrong:
$$\frac{\partial f}{\partial x}$$
is the partial derivative of f with respect to x. Sometimes (sloppily in my opinion) read as "partial f partial x".

$$\nabla f$$
is the gradient of f or "del f" or "nabla f".

9. Oct 17, 2007

### CRGreathouse

I understand the differences between gradient and partial. But between the fact that I usually hear it said that way, and the fact that the partial symbol $\partial$ resembles a reversed delta $\delta$ it seems a lost cause.

Frankly I rarely discuss analysis aloud with others, as my interests tend more toward number theory.

10. Oct 17, 2007

### LukeD

With the symbol $$\frac{\partial a}{\partial b}$$, you'll get a lot of disagreement. I've never seen a standard name for it, but many people call the $$\partial$$ symbol del, or just partial, which, despite the informality, I find is more accurate and leaves out any confusion since the symbol isn't actually called a del.

As people have pointed out, del refers to $$\nabla$$, which is also named nabla (meaning harp), though I more often hear it called by exact usage since it can be the symbol for curl, divergence, gradient, laplacian, etc

Another pronunciation of the symbols $$\frac{\partial}{\partial x}$$ and $$\frac{\text{d}}{\text{d}x}$$ is partial by partial x and dee by dee x or sometimes you'll hear partial over partial x and dee over dee x. Basically, there are a lot of words you can stick in there and have it make sense. The most common ones are over, by and of. Sometimes, this can get a little confusing because you'll hear something like "dee of dee x of f" meaning $$\frac{\text{d}}{\text{d}x}f$$

11. Oct 17, 2007

### Diffy

I don't know if this is an American thing or not but for that first one I would say "Eight point two three times ten to the negative thirty fifth" Saying "ten to the negative thirty five" is wierd to me.

You wouldn't say "Ten to the three power", You would say "ten to the third power" , right?

But again maybe this is an american thing, you strange Europeans always say Maths as opposed to just math.

12. Oct 17, 2007

### CRGreathouse

I'm American, but I grew up in Europe. (Wales, though, not the Continent itself.) I sound American (in particular, almost precisely what linguists call General American), not the Queen's English.

I do say "Ten cubed", "ten to the third power", "ten to the power of three", or simply "ten to the three". I don't say "ten to the three power" or "ten to the power of third". I sometimes say "ten to the third".

Actually I thought the contentious item would be my use of "negative" rather than "minus". I always say "negative three" rather than "minus three" though I hear the latter more often than the former.

13. Oct 17, 2007

### Diffy

Just out of curiousity can you explain the Math vs Maths thing?

14. Oct 18, 2007

### cristo

Staff Emeritus
There's really nothing to explain: they are just two different ways of shortening a word. Americans do this: mathematics -> math' whereas Europeans (or at least British) do this: mathematics -> math's. (Techincally, I suppose we should always write the apostrophes, but noone does).

15. Oct 21, 2007