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Ask HN: How do I improve my command of mathematical language?

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Re: Ask HN: How do I improve my command of mathematical language?

#11
post #3

The issue is here: "I have no problem solving most of algebra or calculus problems, but if you asked me to explain what I'm doing I wouldn't be able to tell you, at least not using mathematical constructs/words." This is slightly unclear; there are two possible problems here from what I can see, and they're totally different problems to have. Either you cannot do maths, and you're only good at solving repetitive prob…

The problems in Spivak are pretty good I think - they'll show if you can do maths or not. Some also have answers (and an answer book for the rest), so there's examples of explaining what was done, for harder ones. The explanations are sometimes too concise, but at least it gives some guide for how you can explain your answers. At a much easier level, Khan Academy videos mostly are explaining how a specific problem wa…

Meh. Everyone pushes their favorite calculus book but I think better is to just try to push yourself to gain an intuition for your subject. Try to visualize what it is the text is saying, try to apply the problem etc.

When I took calculus there were three things that really helped me with this:

1) A study partner that's competitive. when you have an intuition you're more likely to get the correct answer first because you can check what's going on quickly without having to recalculate things. Also when they get stuck you'll be expected to explain how you figured it out. Studying with someone like this will force you to grow an intuition.

2) Writing programs that use what you've learned. At least for me this helped a lot. I learned to program before I learned any interesting math so being able to rewrite what are often implicit ideas in an explicit language can really help you think things through. Like many people here I gained an intuition for integration early on by writing physics engines for games.

3) Just meditate on the ideas.

Re: Ask HN: How do I improve my command of mathematical language?

#12

Instruct. Explaining it to other people is helpful for developing your ability to express mathematical ideas (any idea really). You'll learn where you're limited in expressing your understanding and be forced to develop the language.

This is the right answer. If you think you understand something, pretend that you have to teach it to a beginner and write a short lecture/presentation to give them. Explain what they'll be doing, why, and why it is important. Do it in which ever language is most comfortable. If you can prepare that lesson then great. If you cannot, then your initial assumption that you understood the material was incorrect. Mathematicians write material like this all the time (they like to call it "expository material").

Re: Ask HN: How do I improve my command of mathematical language?

#14
post #7

I feel like I have some kind of mathematics dyslexia. I can understand all the concepts, but I find formal mathematical notation almost completely incomprehensible. Expressions with all kinds of strange symbols, often variables introduced that are either completely undefined or defined ad hoc locations remote from the usage, integrals and sums with no subscripts / unclear scoping, etc etc. Clearly other people just r…

> Expressions with all kinds of strange symbols, often variables introduced that are either completely undefined or defined ad hoc locations remote from the usage, integrals and sums with no subscripts / unclear scoping, etc etc.

This is what mathematical notation looks like if you are lacking some of the fundamental knowledge to read it. I know what that's like because I've been there. Learning mathematics like you would programming doesn't really work - because often you can't just look up something you don't understand (how can you Google a mathematical symbol when you don't even know it's name?).

Pretty much the only way to learn mathematics is from the ground up.

> and I even know people who will ignore all the text in a paper and just look for the equations

Mathematical notation is mostly a substitute for words and that's why those equations can be embedded in natural language and "read". Ignoring the words in a mathematical paper and just looking at the "funny symbols" doesn't make any sense. You're only seeing tiny glimpses of the actual reasoning and are probably missing most of it.

A mathematician may chose to write "B contains all elements of A, and A contains the element x.", or they may chose to write "A ⊆ B and x ∈ A". Same thing. Also note how the second example still had an english word in the middle of it. If that "and" was an "or" the sentence would have an entirely different meaning. Can't just ignore that stuff.

Sure you could replace that "and" with yet another symbol, and in something as simple as that nobody would really care, but in something more complex the mathematician would just be trying to produce an unreadable mess on purpose.

Re: Ask HN: How do I improve my command of mathematical language?

#15
post #7

I feel like I have some kind of mathematics dyslexia. I can understand all the concepts, but I find formal mathematical notation almost completely incomprehensible. Expressions with all kinds of strange symbols, often variables introduced that are either completely undefined or defined ad hoc locations remote from the usage, integrals and sums with no subscripts / unclear scoping, etc etc. Clearly other people just r…

> integrals and sums with no subscripts / unclear scoping, etc

That’s just seems like bad writing. Out of math subjects I learned (discrete math, linear algebra, real analysis, statistics), only in the last one it may be unclear what’s going on, whether you are dealing with a random variable or its realization, and arguments of random variables are almost always omitted, so they don’t look like functions.

Re: Ask HN: How do I improve my command of mathematical language?

#17
If you want to improve your oral presentation, you need to practice your oral presentation. Doing problems on paper and hoping your verbal description will improve is not going to work.

I suggest you find some maths videos on Youtube which explain maths you already know with lots of verbal detail narrating each step. Pay attention to the words and description (you already know the maths), then try talking through your own working in the same way. You could record yourself and watch it back (camera pointing straight down at paper is good, and phone camera held up on a ruler and stack of books is easy). As others have suggested, once you can do that to some extent, explaining things to others can be good practice, but if you're stumped as to how to describe anything, that's not going to be a good first step.

I teach university maths, and when I'm doing a problem in a lecture, writing down the steps to demonstrate, I am constantly talking, narrating everything I'm doing and why. E.g. "Okay, we need to cancel out that 3, so let's divide both sides by 3, and then we can use log rules to bring that 2 on the right inside the log as a power. Now to cancel out these logs we need to use an exponential on both sides, and if we move these terms over we'll have a quadratic to solve. We know how to do that! Hm, it doesn't seem easy to factorise, so let's complete the square. We need half of this coefficient to go inside the brackets, and don't forget the minus is part of it! Now if we think about expanding this out we'll get the x squared and minus 4 x that we want, but also a plus 4, so let's take that away and add on the 3 we need instead ..."

I'll also be referring to the context of the problem ("that makes sense, because ..." etc.) and earlier examples to compare and contrast with.

Re: Ask HN: How do I improve my command of mathematical language?

#18
post #7

I feel like I have some kind of mathematics dyslexia. I can understand all the concepts, but I find formal mathematical notation almost completely incomprehensible. Expressions with all kinds of strange symbols, often variables introduced that are either completely undefined or defined ad hoc locations remote from the usage, integrals and sums with no subscripts / unclear scoping, etc etc. Clearly other people just r…

Don't feel too bad about it, there are far too many notations for the same concepts - completely dependent on the background of the author.

This becomes especially noticeable in hodgepodge fields like Machine Learning / Deep Learning, where you essentially have scientists from all walks of life/sciences, trying to convey the same ideas, but using their own standards of notation.

Check out this Math Overflow answer from none other than Terry Tao, on inner product notation: https://mathoverflow.net/questions/366070/what-are-the-benef...

Point is - he listed 18 different notations, on the spot, all "belonging" to different fields. Now imagine 18 different scientist, from their respective fields, writing research papers using their preferred notation.

Sure, there's going to be a lot of overlap - but there's still room for confusion, even for seasoned engineers and scientists.

(I just used ML and DL as an example, because that's the field where I've noticed the most of this - because of the nature of those fields)

Re: Ask HN: How do I improve my command of mathematical language?

#20
post #6

Have you done (or seen) math proofs? If not, the following FREE book can serve as a great starting point for learning how to get your point across in the most clear, complete and concise way. Algorithms you see in elementary algebra (as opposed to, say, abstract algebra) and calculus are just that -- algos[0]. They teach you neither math, nor critical thinking. Book Of Proof by Richard Hammack https://www.people.vcu.…

I strongly agree with this, you already have enough math knowledge to learn how to do basic proofs. Hammack’s book is great, and it’s great that the author made it freely available. I personally used Chartrand’s “mathematical proofs” and thought it was very helpful, I like it a little better than Hammack’s book, but they are both great for people getting started, particularly for self-study.

You also need to talk to other humans about math on a regular basis - feel free to contact me, I love talking math! Contact info is in my profile.

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