Questions tagged [notation]
For questions about good use of notation, comparison of specific notation, motivation of notation.
76
questions
6
votes
3answers
327 views
What's a good notation to show elements of relation composition?
Teaching discrete mathematics, we pose (from the textbook) questions on finding compositions of relations, notably, relations on very small finite sets with only 3 or 4 elements (as an introductory ...
6
votes
6answers
541 views
Why do we write $x$ instead of $1x$?
I am currently student teaching for an Integrated Math 1 class (which is similar to Algebra 1) that consists of 9th graders. I have been teaching my students how to solve linear systems using ...
7
votes
7answers
3k views
What is the preferred way to denote the Pythagorean theorem equation?
I am teaching 12-16 year olds.
How should I write down the Pythagorean theorem equation?
Some alternatives:
$a^2 + b^2 = c^2$
$\text{leg}^2 + \text{leg}^2 = \text{hypotenuse}^2$
$\text{leg}_1^2 + \...
4
votes
7answers
278 views
Should I avoid writing: $ 11:40 - 15 \text{ min} = 11:25$, and what are alternatives to this way of writing?
I want to stress to my students that we should be careful with how we treat the equals sign and that we should always make sure that the units match. However, sometimes I write
$
11:40 - 15 \text{ min}...
19
votes
11answers
5k views
Why do we still teach the determinant formula for cross product? And is it as bad as I think it is?
The cross product is an important vector operation in in any serious multivariable calculus course. In most textbooks that I'm aware of, right after the definition, we always introduce the ...
8
votes
2answers
304 views
Question about function notation
In the textbook I am using to teach mathematics to high school students I found the following illustration about composition of functions.
I do not agree with this illustration. For me $g$ is the ...
10
votes
6answers
2k views
What is the right notation to use in multivariable chain rules?
The following "chain rule" is in my multivariable calculus course:
If $f$ depends on $x$ and $y$, but $x$ and $y$ depend on $t$, then $\frac{df}{dt} = \frac{\partial f}{\partial x} \frac{d ...
9
votes
2answers
513 views
Fear of notation and hazily-appeared writing in Mathematics
I am looking for literature related to fear of notation in mathematics.
It is even heard that the font size and font type make a reader reluctant to study mathematical literature, often lecture notes,...
14
votes
2answers
420 views
The use of “$\therefore$” and “$\because$”
In schools, many students learn the usage of "$\therefore$" and "$\because$" in proofs. Such three-dot notation are popular in many high-school books and exams, but are almost ...
1
vote
1answer
205 views
What to call a symbol that denotes an “undisclosed” given number? [closed]
Students like to categorize notations to pin down their understanding of exactly what these notations stand for. Thus, given the expressions $f(x_{0})=f(x)|_{x\leftarrow x_{0}}$, $x=x_0+h$, or $lim_{x\...
4
votes
3answers
297 views
Students writing $f(x^2+1)$ when they probably mean $f(x)=x^2+1$
Over the past years teaching freshmen calculus I've repeatedly seen students make the following type of error:
Suppose they have to express some quantity $y$ as function of $x$, when the relation ...
4
votes
2answers
197 views
Undergraduate Vector Calculus Notation Mess
Question 1: What are your arguments in favor of the big array of different notations used in the context of undergraduate vector calculus: line integrals, surface integrals (of scalars and fields), ...
32
votes
6answers
3k views
Allowing nonstandard mathematical language and/or notation
How important is enforcing standard mathematical language and/or notation?
Today, I was questioned by a writing instructor as to how vital it is to correct students when they explain something using ...
8
votes
1answer
269 views
Terminology for parts of limit notation
When we talk about: $$\lim_{x\to{c}}f(x)=L$$ Is there a formal name for the number "$c$"?
I know of course that it means "$L$ is the limit of $f(x)$ as $x$ approaches $c$". It just would be nice to be ...
5
votes
1answer
159 views
Notation in the definition of matrix multiplication
When matrix multiplication is introduced, it is usually introduced with an additional variable: Given two multiplicable matrices $A$, $B$, one defines the product $C=AB$ to be the matrix given by some ...
6
votes
3answers
220 views
Are there standard notations for 'number talks' / ‘math talks?'
I’m a homeschool teacher of a nine-year-old, and we sometimes have one-on-one ‘number talks’ (a.k.a. 'math talks') similar to the activity used in primary school classrooms.
Part of this process ...
26
votes
6answers
10k views
Should we stop differentiating between ln and log?
In many U.S. middle schools and high schools, $\ln$ and $\log$ are treated differently, with the intent that $\log$ is equivalent to $\log_{10}$. However, in undergraduate courses and in the academic ...
2
votes
2answers
210 views
How should one approach the concept of “plus or minus”, such as in the numerator of the quadratic formula?
The numerator is structured like:
$$(-b)\pm\sqrt{b^2- 4ac}.$$
Is it confusing or acceptable to distinguish between the following two things?
An idiom; and
What is or seems to be a compositionally ...
7
votes
5answers
2k views
Teaching asymptotic notations at the beginning of calculus [duplicate]
I'm thinking about teaching calculus by firstly introducing the asymptotic notations (big-Oh, little-oh, and $\sim$), secondly explaining their "arithmetic" (things like how to sum little-oh's and ...
6
votes
2answers
212 views
The word “numeral”, is it being taught and does the word exist for it in your language?
I am a mathematics educator from Lithuania and I have recently realized that there is no separate word in our language for the word "numeral". To be more precise there is no term to describe the ...
10
votes
5answers
1k views
A different symbol for the indefinite integral/antiderivative?
Examples. An indefinite integral (or antiderivative) of $\cos$ is $\sin$:
$$\int \cos = \sin.$$
Edit: There has been much unexpected confusion with the above statement. I define the above statement ...
44
votes
21answers
6k views
How to help new students accept function notation
I am struggling to help some of my new precalculus students accept function notation -- something new to them this term. I am looking for strategies to help them adopt this new notation.
Their main ...
3
votes
1answer
154 views
Naming arbitrary constants: subscripts, primes, or just more letters?
When choosing names for arbitrary constants either during a lesson or while working with a single student, should one use$\{n_1,n_2,n_3,\dotsc\}$ or $\{n, n', n'', \dotsc\}$ or $\{a,b,c,\dotsc\}$? Is ...
4
votes
1answer
160 views
What is the notation for polynomial long division in Norway?
I will be teaching a calculus-type course in Norwegian. Our textbook is unfortunately in English (the curse of a small language), but any custom exercises should be and all exams have to be in ...
7
votes
3answers
1k views
Notation for change of basis matrix
As far as I can tell, it's only a slight exaggeration to say that every text has a different notation for a change of basis matrix from (say) $\mathcal{B}$ to $\mathcal{C}$. That's not even to talk ...
11
votes
3answers
495 views
Are there any negative consequences in applying operations/functions to a whole equality?
Some of my students solve equations not by applying the same operations on the left and right sides of an equation, but by applying the operation to the whole equality. For example, they may write ...
7
votes
4answers
584 views
In teaching mathematics, should one always follow some international standards such as ISO 80000-2?
ISO 80000-2:2009 is a standard describing mathematical signs and symbols developed by the International Organization for Standardization (ISO). In teaching mathematics, should one always follow this ...
-1
votes
1answer
200 views
Duodecimal by Stealth
It is widely recognised that the Duodecimal number system is superior to the decimal system. However, it is plainly obvious that trying to introduce such a system would be difficult, especially in a ...
11
votes
4answers
848 views
Multiple students writing $y\frac{d}{dx}$ rather than $\frac{d}{dx}y$ — why?
I'm currently teaching a couple of courses that have a calculus prerequisite, and within the last week I've had two students make notational mistakes that amount to writing $y\frac{d}{dx}$ rather than ...
1
vote
1answer
182 views
Can $y^{(n)}$ be used as a way of representing higher order derivatives?
I have never seen this notation, but I think that it follows in a similar vein for function notation. So if $y=f(x)$, then $y''=f''(x)$.
Then by that, can we say that
$$f^{(n)}(x)=y^{(n)}$$
20
votes
5answers
665 views
How students write their work, and learning outcomes
While teaching students mathematics, I have noticed that some seem sloppy in the way that they write down their work.
For example, a student is given a question: What is the area of the rectangle?
<...
6
votes
4answers
567 views
Who actually uses $\mathbf i$, $\mathbf j$, $\mathbf k$ for the standard unit vectors?
I am wondering which research communities use the notation $\mathbf i$, $\mathbf j$, $\mathbf k$ for the three-dimensional unit vectors. The calculus textbook I have to use (Stewart) uses that ...
10
votes
3answers
375 views
Framework for Compound Inequalities
I have been presenting compound inequalities like
$3 < x < 7$
as being a shorter way of saying
$3 < x$ and $x < 7$.
From this point of view, though, I end up having to admit that ...
7
votes
2answers
3k views
Is “hat notation” for unit vectors commonly used in mathematics?
As an undergraduate, I clearly remember learning and using "hat notation" to describe unit vectors. That is, if $\vec{v}$ is any vector (in 2 or 3 dimensions) then $\hat{v}$ denotes the unit vector ...
15
votes
5answers
846 views
Why is multiplication taught using cross notation at first?
Alert: I am not a math educator.
It seems to me that multiplication is first taught using the cross notation, for example $3\times 5=15$.
First question - is that even correct? Maybe not all schools ...
13
votes
5answers
1k views
Writing Fractions “Correctly”
I very often see students writing, for example, $1/3x$ when they mean
$\frac 13x$. I used to tell them not to write $1/3x$ beause it looks like $\frac{1}{3x}$ until I realized that, according to ...
18
votes
3answers
1k views
Why are $m$ and $b$ used in the slope-intercept equation of a line?
The slope-intercept form of the equation of a line is often presented in textbooks (in the US) as
$$y = mx + b\,,$$
where $m$ is the slope of the line and $b$ is the $y$-intercept. How did $m$ and $...
4
votes
2answers
138 views
What is the role of the efforts to change the fundamentals of maths? [closed]
One is often drawn to offbeat mathematical ideas and how they could revolutionize mathematics or at least make maths more easy to learn.
Current examples are:
Rational Trigonometry
Tau
Dozenal
...
6
votes
3answers
408 views
Wording VS mathematical notations
Is it better to write everything in words as the concepts themselves should be known? Or will some teachers in some countries prefer to be able to choose questions which also test the student's ...
21
votes
5answers
3k views
Grating mathematical phrases---How to correct?
As mathematics educators, we all have come across students using mathematical notation incorrectly (looking at you, $\frac{d}{dx}$ vs $\frac{dy}{dx}$ or $\frac{\infty^2}{\infty}$). My question focuses ...
12
votes
1answer
351 views
Why do some of my, usually international/Indian students, write limits to the left of the integral?
I see a lot of my students (I am in the US), usually Indian, write the limits of integration to the LEFT of the integral sign rather than customary top or right. The formula will look for example like ...
5
votes
2answers
209 views
At what educational stage are angles greater than 180 introduced?
Prompted by the question,
"How to denote angle?,"
I am interested to learn when students consider and reason with
angles $> 180^\circ$.
For example, when do they reason with an angle of $270^\...
11
votes
1answer
889 views
How to denote angle?
I'm teaching mathematics on my free time for young pupils. Once I have seen that they denote angles like $\angle ABC$. But sometimes I have difficulties to understand whether they mean an angle or its ...
7
votes
3answers
250 views
Design of a math exam using multiple choice or computer
I'm teaching math in first years of university (matrix algebra, differential analysis, etc.) since maybe 5 years, and I usually give written (paper) exams to the students.
I'm looking for ideas to ...
28
votes
6answers
6k views
Misuse of parentheses for multiplication
I'd like to raise the issue of constant misuse of parentheses in the U.S., and I'm wondering if anybody else shares the same feelings, has had the same issues, knows any history behind it, and can ...
6
votes
2answers
217 views
How to reasonably denote lines, line segments and rays?
I'm teaching geometry at high school for the first time soon and am struggling to find a reasonable notation for lines, line segments and rays defined by two points $A$, $B$ (and a direction). At the ...
4
votes
2answers
6k views
Notation of line segment and its length
I have sometimes seen a notation where $AB$ could mean either the line segment or its length. Why do the same notation can be mean both? Should one teach pupils to use for example notation $d(A,B)$ or ...
12
votes
8answers
11k views
Proof of why BODMAS (or BIDMAS) works?
In my first full-time teaching post, it is very likely that I'll need to be teaching a small amount of GCSE Mathematics to students retaking it. One thing that has been bugging me is that I can't seem ...
3
votes
1answer
343 views
How to explain “fractional terms”?
as I can see there are mainly two ways to introduce fractional terms. Two examples to demonstrate the two variants:
$\frac{a^2+3}{a}; \frac{3}{2c}$
$T(a) = \frac{a^2+3}{a}; T(c) = \frac{3}{2c}$.
In ...
16
votes
4answers
631 views
Do students confuse $\log_ab$ and $\log a^b$?
I recently observed a group of students being introduced to logarithms for the first time.
Some of them had trouble writing $\log_ab$ properly, and it looked more like $\log a^b$.
All logarithms have ...
