# Tagged Questions

This tag is for questions about the usage and meaning of mathematical terminology and the names for mathematical entities in English.

16k views

### What do you call a disk with a hole in the middle?

Compact Discs, washers and Aerobie frisbees are all disks with a hole in the middle. Is there a word (either mathematical or not) to describe this shape? I mean the specific case of a round hole in a ...
15k views

In mathematics, quadratic means "involving the second and no higher power of an unknown quantity or variable". But the prefix quad- usually describes something that has to do with four, such as quad-...
8k views

### How to read “E = (mc)²” so as not to mistake for “E = mc²”

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”?
9k views

### Is -1 singular or plural?

Do we say "-1 thing" or "-1 things"? I am interested in both two things minus one thing(s) and minus/negative one thing(s)
44k views

### Use of “I”, “we” and the passive voice in a scientific thesis [duplicate]

Possible Duplicate: Style Question: Use of “we” vs. “I” vs. passive voice in a dissertation When the first person voice is used in scientific writing it is mostly used ...
31k views

### X, Y, Z — horizontal, vertical and …?

When working in a 2D coordinate system you could say that X is the horizontal axis and Y is the vertical axis. Extending this to 3D, is there a similar word for the Z axis? (I'm aware of Width, ...
5k views

### Rhetoric vs. Mathematics: ellipsis/ellipse, parable/parabola, hyperbole/hyperbola

Do ellipsis, parable, and hyperbole from rhetoric have anything in common with the geometric curves ellipse, parabola, and hyperbola used in mathematics? There are three geometric curves known as ...
4k views

### (k+1)th or (k+1)st?

Mathematicians commonly have to form ordinals from variables: you might look at the kth element of a sequence, for example. When the variable is a single letter, the ordinal is always formed with the ...
4k views

### How is a' in mathematics pronounced?

It often happens that two or more similar values are distinguished with the ' symbol, e.g. a, a', a'' and similar. How is this pronounced?
23k views

### Difference between “computation” and “calculation”

If the words computation and calculation are not perfect synonyms what is the difference between them? Which one describes more accurately what is done by a person computing or calculating something ...
3k views

### Is “iff” considered a real word or just an abbreviation?

I wonder if "iff" is considered a real word (as LEO says) or is it just an abbreviation (as in Wiktionary)?
29k views

### How to read exponential expressions, e.g., “2^16”?

How do you say the mathematical function in English: x^y (or xy) For example, how do you say 2^16 (or 216) I know ^ means 'power' or 'exponentiate', but that is the name of the operation,...
1k views

### What's the name of this letter? [closed]

I came upon this letter when reading a book, I couldn't find its name on the internet, you can imagine how hard it is to search about it. What is the name of the letter that follows "sample space"? ...
3k views

### Transform or transformation?

Is there a difference between the words transform (noun) and transformation? Let me describe my problem. I have a mathematical model which I can transform into a better model with help of a data ...
18k views

### Does “either A or B ” preclude “both A and B”?

In mathematics, "A or B" includes "A and B". Does "either" mean "A or B but not (A and B)" or does it include the possibility of "A and B"? The context might be mathematics, formal logic or ordinary ...
4k views

### Where does the word “totient” come from?

In math we learn about the "totient function". It rhymes with "quotient" when math teachers pronounce it. But I cannot find the definition or etymology of this word in any dictionary, nor on any web-...
7k views

### Why do we say “lowest common denominator” when we mean “greatest common divisor”?

For example, we could say HTML is the lowest common denominator on the web", because one can be sure all web browsers are able to render HTML (but not Flash or Java). If I want my web page to show ...
1k views

### What is the term for an integer one larger than a given integer?

I'm looking for a concise term to say a number must be exactly one higher than a previous number. None of "subsequent", "incremental", or "next" seem to convey the restriction that it must be ...
12k views

### Trapezium/trapezoid — why are the US/UK definitions swapped around?

These are the US definitions... Trapezoid — a 4-sided flat shape with straight sides that has a pair of opposite sides parallel. Trapezium — a 4-sided flat shape with straight sides and NO parallel ...
4k views

### Is there a shorter term for “divided by” in American English?

Given the following expression: 5 (+-×÷%) 4 You would say "5 plus 4," "5 minus 4," "5 times 4," "5 divided by 4," and "5 mod(ulo) 4" respectively. As far as I know, "divided by" does not have ...
4k views

### How to pronounce fractions larger than a twentieth, where the last digit of the denominator is a 1 or a 2? i.e. one thirtieth is to 30 as _ is to 31

Disclaimer: I speak British English. I've noticed a lot of differences between the way Americans and Brits pronounce numbers.1 Since the question concerns this, I thought it might be appropriate to ...
7k views

### What do you call a cylinder with a hole down the center?

Imagine a 3D cylinder, like a can. Now imagine that almost like an axle spot for a wheel, there's a hole shaped in a perfect circle going down the cylinder. That's the shape I have to figure out the ...
1k views

### What is the proper term for a ternary digit?

A binary digit is a bit. Is there an equivalent term for a three-state digit? (e.g., a digit representing true, false, or unknown)
9k views

### How can I form a word like “quadruple” for any number I want?

I'm not sure what these are called, but how can I form a word like "quadruple" for any number I want? Like 5× as much is quintuple, what is 31× as much or 147× as much? I want to know how they are ...
8k views

### What reasoning is behind the names of the trigonometric functions “sine”, “secant” and “tangent”?

The meanings of these words are very similar: the sine of an angle in a right triangle is the ratio of the opposite side to the hypotenuse; the secant is the ratio of the hypotenuse to the adjacent ...
3k views

### What is an adjective for a very large negative number?

A number that is very large (but not infinite) such as 1,000,000,000,000,000 could be called huge, enormous, large, big, gigantic, etc. A number that is very small such as 0.000000001 could be called ...
7k views

### “Parametrise” or “parameterise” a curve?

In British English, which one is correct? Does one parameterise a curve or parametrise it?
17k views

### Should I use the singular or plural verb in mathematical formulae (“Two and two make/makes four”)?

I remember somebody correcting me once when I said, "Two and two makes four", since the conjunction and would imply the use of a plural verb. They would prefer I said: Two and two make four. I'...
2k views

### Pronunciation of the big-O notation

How should I pronounce the following things? (These are complexities of algorithms.) O(n) O(n*log(n)) O(n^2)
49k views

### Are there any differences between “oval” and “ellipse”?

Are there any differences between "oval" and "ellipse"?
15k views

### “Lower number” vs. “smaller number”

Is −9 a smaller number than −8? And is −9 a lower number than −8? What is the difference between lower and smaller here?
3k views

### What is the derivation of the statistical term “Histogram”?

There are conflicting definitions of origin. Unclear as to whether it is derived directly from the Greek, coined by Pearson, or used and named prior to Pearson. Refer to "The History of Histograms - ...
1k views

### Use of an Apostrophe in Maths Place Values

In mathematics, when you're discussing the concepts behind different number bases, it's often necessary to refer to a digit's place. For example, in the following "base 10" number (the number system ...
5k views

### How to pronounce “nₒ” properly

People here (Hong Kong) like to pronounce n0 ("n subscript zero") as "N-nor"; "N-zero" seems to be acceptable. I am wondering what's the most popular pronunciation in English. I am actually a little ...
1k views

### Etymology of “regression”

What is the etymology of "regression" as in finding the coefficients of polynomials?
72k views

### Why is “a 100% increase” the same amount as “a two-fold increase”?

and is such interpretation the norm? When something went from 4 units to 8 units, most authoritative sources seem to agree with the use of "a two-fold increase", even though what was actually ...
237 views

### How to punctuate math fractions?

I was doing the Writing and interpreting decimals exercise on Khan Academy and was asked the following question: What is nine and three hundred two thousandths in numerical form? I read it as "...
2k views

### The Condition Holds vs is Satisfied vs Obtains

In mathematical/scientific texts, conditions that are true (within context) are said to hold be satisfied obtain (the last one was news for me) My question is whether there is nuance in meaning ...
2k views

### How can I describe a “one or more” condition (one that has many options; a “non-boolean”)?

Generally speaking a boolean condition is understood to be an "either/or" relationship; for example, something is hot or cold. What's do you call a "one or more" condition, e.g. something that can ...
3k views

### When do we use “suppose” and when “let”?

As a matter of fact, these two words are used a lot in mathematical contexts. Often, we use them interchangeably; but I do realize that that might not be correct. What should I do about this matter? ...
3k views

### Is there a word for a class of circular shapes?

I'm not sure if this belongs here, but I'm wondering if there is a word for a class of circular shapes? Thinking about this hierarchically: * Shape * Polygon * Square * Rectangle * ??????...
42k views

### “an hour and a half” or “one and a half hours”

Are both "an hour and a half" and "one and a half hours" correct? If so, is either more appropriate in different contexts? Example context: "The Superbowl starts in less than one and a half hours....
624 views

### “That… be” construction

We will make the convention that exact categories be skeletally small. Is this construction (used in a mathematical context) correct? There is something that strikes me as odd in that "be". Should ...
586 views

Mathematical notations are usually called symbols in the large, yet particular symbols seem to be blessed, they are often called signs ('equals sign', 'multiplication sign', ...). Is there a ...
1k views

### Is there a word for opposite numbers?

Example: -100 and +100 - is there a way of describing the relationship between these numbers? Obviously, I've already come up with "opposite", is there anything else? This is for use in an email. ...
19k views

### Divide two into four and Divide two by four

Why does "divide two into four" equal two, and "divide two by four" equal one half? Correct if I am wrong, but this what I have learned recently.
757 views

### Etymology of “magma” in abstract algebra

Magma is one of those beautiful words of Greek origin (μάγμα) that arouses the child and the wild in me, making me think of volcanoes. I just found out, though, that it is also used in mathematics to ...
8k views

### “integer multiple” vs. “integral multiple”

Nine is an integer multiple of three. Nine is an integral multiple of three. Which is more common? If both are accepted, what's the subtle difference between them?