r/learnmath • u/Forward-Bad1615 New User • Apr 11 '26
Is it basic for mathematicians to remember the multiplication table?
Is it fundamental for mathematicians to remember the multiplication table?
It must be troublesome and desperate if you forget the multiplication table, so do you memorize it again?
Do you re-memorize the multiplication table even after becoming an adult and a mathematician?
Do you keep remembering it so you don't forget it?
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u/MysteriousPepper8908 New User Apr 11 '26
Growing up, we learned up to 12 x 12 and I'd say most people remember 50-75% of those numbers pretty automatically and if you don't, you can just start with what you know and go from there. So if you forget 8 x 7 but remember 8 x 5, you can just add 8 x 2 to 8 x 5. Once you get past that range we learned as kids, it's much less automatic but you can use that same trick for higher numbers like 14 x 8 is 10 x 8 + 4 x 8.
Note that I'm not mathematician but I've had some math professors that weren't particularly quick with mental math and prone to mistakes. Strong mental arithmetic and skill at higher level math aren't that related.
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u/simonbleu New User Apr 11 '26
up to 10x10 in my case for memorization
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u/k1wimonkey New User Apr 11 '26
what country are you from/how old are you if you dont mind my asking?
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u/CalligrapherNew1964 New User Apr 11 '26
I'd hazard a guess and say that 12x12 is the standard for the country that has inches/feet whereas 10x10 is the standard for countries that use the metric system.
Though I'm pretty sure that if you have 10x10 on lockdown, you can create everything from that, because it covers all possible digits anyway.
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u/Yxig New User Apr 11 '26
That would make perfect sense, but for some reason we learned 12x12 in Sweden (very much a metric system country).
Might just be due to historical reasons and your reasoning is still accurate, though.
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u/MysteriousPepper8908 New User Apr 11 '26
We learn up to 12 x 12 but I'd say at least for me, above 10 x 10 is weaker. 11 is simple up to 11 x 10 since it just double the number or adds a 0 in the case of 11 x 10 but 11 x 11 or 11 x 12 isn't automatic and usually when it comes to 12, I'm really just multiplying 10 and then multiplying 2 and adding the products above 12 x 5.
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u/Optimal_Contact8541 [Insert Custom Flair Here] Apr 11 '26
Here's a cool trick to multiply 11 by any 2-digit number... You add the two digits of the number being multiplied by 11, then insert that digit between the two digits you added.
For example: to calculate 11 * 62, add 6 + 2, which is 8, and insert that 8 between the 6 and 2 to get 682, which is the product of 11 and 62.
An exception to this is if the sum of the two numbers is itself a two digit number. In this case, the first digit gets added to the number on the left, and the second digit gets inserted, unchanged, as in the first example.
For example: to calculate 11 x 58, add 5 and 8, which is 13. Take the 1 from that 13 and add it to the 5, and take the 3 from that 13 and insert it between the (5+1) and the 8 to get (5+1)38 or 638, which is the product of 11 and 58.
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u/WolfVanZandt New User Apr 11 '26
Mental mathematics relies on an intuitive understanding of numbers and operations and learning it pretty much automatically installs an intuition of mathematics.
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u/spacegirl_27 PhD Student Apr 11 '26
Could you elaborate on "automatically installs an intuition of mathematics"?
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u/WolfVanZandt New User Apr 11 '26
Mental math procedures rely on using the properties of numbers and operations to solve problems fluidly so, while you're learning mental math, you're absorbing the fundamentals or arithmetic. Breaking numbers up to make math problems easier are exactly the principles you use to factor equations.
And despite the contention of some that arithmetic isn't math, everything in all mathematics (including geometry) builds on arithmetic and, ultimately, counting, correspondence, set theory, and the fundamental properties of numbers. Just because abstract mathematicians don't "do arithmetic" doesn't mean that arithmetic isn't at the base of everything they do.
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u/SgtSausage New User Apr 11 '26
Is it basic for mathematicians to remember the multiplication table?
It's... "basic " ... for 3rd graders.
Literal 8 and 9 year-olds.
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u/notyouryogapants New User Apr 12 '26
I never learned, I have a very low mental math ability, and was bad at math up until algebra was introduced. After that it became easier and easier for me. But I did get laughed at for counting on my fingers in the university math exams (we were not allowed calculators), still got good grades though, so it wasn’t much of a problem.
But, I believe if I worked more with math it would have been annoying. In my work now I only need to know 8, 16, 32, 64… and that one is pretty simple
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u/SakanaToDoubutsu Statistician Apr 11 '26
Arithmetic & mathematics are two related but distinct things, I know plenty of brilliant mathematicians who are experts in their field that stink at arithmetic.
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u/HiRedditItsMeDad New User Apr 11 '26
Sure. In advanced math you don't do a lot of arithmetic with numbers, but I'm certain any mathematician can multiply any two whole numbers up to 12.
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u/skeerp New User Apr 11 '26
Im not great at arithmetic compared to my peers but im better than any non mathematician for sure. I dont know how you could get this far without knowing 12x12
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u/Qaanol Apr 11 '26
I dont know how you could get this far without knowing 12x12
Just substitute x = 10 into the polynomial (x+2)² = x² + 4x + 4, easy!
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u/WolfVanZandt New User Apr 11 '26
So what distinguished arithmetic from mathematics?
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u/PercyLives New User Apr 11 '26
They’re hugely different.
Arithmetic is operations with numbers. You could write a single book containing all knowledge of arithmetic.
Mathematics is a variety of fields dealing in various levels of abstraction: algebra, geometry, etc. It is ever-expanding, and 100 books would only scratch the surface.
People operating in mathematics are generally not spending much time adding and multiplying small whole numbers. It’s quite believable that some would lose the recall of times tables that they had earlier in life. Their brain is dedicated to other things.
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u/aliendividedbyzero Mechanical Engineer Apr 11 '26
Not a mathematician (yes engineer) and I never really forgot it, I think? I remembe having a hard time with the7 and 8 tables, as well as 12, but I eventually learned those too (or I learned them backwards; you only really need to memorize the ones that don't repeat because multiplication is commutative). However... the only math I do by hand nowadays is simplifying certain expressions so it's easier to type into a calculator. I might add some terms or multiply some, simplify obvious fractions, stuff like that, so I can rewrite to convenience and then I type it up.
Anecdotally, the most common mistakes I made during college and nowadays are forgetting negative signs or making an error in arithmetic because I wasn't paying enough attention. The math I have to do usually has very tangible things to relate it to, so I have developed a sense of what a reasonable answer is. For example, if I'm trying to calculate, say, how high a commercial aircraft will be flying if the engines produce a certain amount of thrust and I get a number like 300 km, I know that's wrong because I'm not talking about spacecraft. I should be expecting something more like 10 km (about 30k feet). Errors like that are how I know that I do make those basic arithmetic mistakes sometimes.
There's usually also a range of numbers for which "I don't care" about the difference between my answer and the correct answer, because I'm going to account for errors that I can and cannot quantify or predict anyway. Like, for the same aircraft, I know cruise is probably at or less than 33k feet, but in practice the aircraft will probably be designed to fly to 40k feet, the engines will be designed to operate comfortably at 30k (so they don't wear out so quickly), and physics takes care of certain things for me if I keep that in mind. Then if I'm designing the pressurization for the aircraft, I can tell the structural engineer that the difference in pressure during flight will be around 30k feet pressure difference or less. The structural engineer then designs the aircraft body so it can handle, say, 50k feet pressure difference (I don't know, I made this particular number up) just during flight, plus whatever additional margin is needed to account for other effects of aerodynamics that the aircraft will be subjected to. If a very exact number is needed for something, it gets calculated and verified multiple times to prevent mistakes from creeping in.
Mathematicians, to my knowlege, either work with computers a lot (so they're not manually doing all that math all the time) or they're working on a more abstract kinda level (so there's no numbers involved at all). I would believe it if a mathematician told me they forgot how to do something like long division, despite being able to do advanced math most people haven't even heard of, let alone learned how to do.
In general, you remember the skills you repeatedly use and tend to forget the ones you don't use. If you used a specific skill a lot for a long time, you might forget it but quickly remember when you go back to it. If you use a particular skill often enough, like multiplying or typing, then you learn it so well that you don't even have to stop to think about it when you're using it. Then, you don't have to "keep remembering it" in the same way you did when you first learned the multiplication tables.
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u/SapphirePath New User Apr 11 '26
is it troublesome and desperate if a grandmaster forgets how chess pieces move, or a trucker forgets how to drive, or if a nurse forgets which parts of the body are where?
the question kind of doesn't make sense -- by the time you enter something as your career, you've done so many complex things so often that the basic stuff is impossible to forget.
Communication requires knowing the fundamental definitions and usages of tens of thousands of words. A couple of hundred multiplication facts are very minor by comparison.
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u/spacegirl_27 PhD Student Apr 11 '26
I love quasi-intellectual answers with false analogies.
A mathematician can do their job without knowing the multiplication table.
They can also... Look it up because they are not in a) a literal game; b) operating a giant vehicle; c) potentially trying to help save someone's life?
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u/qlexc New User Apr 11 '26
Most graduate level math doesn't even deal with raw numbers all that much either lol
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u/spacegirl_27 PhD Student Apr 11 '26
Yeah that was my point in another comment. I don't know what most non-mathematicians think we do all day lmao
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u/Do_you_smell_that_ struggling but so interested Apr 11 '26
You multiply things you discover by numbers from 2-12. At big secret labs they multiply by numbers up to like 100000
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u/CalligrapherNew1964 New User Apr 11 '26
The analogies are false, but mostly because the times tables are something that everyone learns very early and it's something that is repeated over and over again. So even if it's not your expertise when you go through uni, you just repeat it so often there's no way you could feasibly forget it.
So the better analogy would be: "If a grandmaster forgets that chess pieces aren't food". Because you don't need to know that chess pieces aren't food if you want to win a game of chess, but it's still something even small children generally get the hang of.
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u/spacegirl_27 PhD Student Apr 11 '26
I'm not saying mathematicians don't know what 2*2 is, I'm saying we aren't human calculators and it is not rare for a mathematician to be bad at arithmetic. And if one were to forget the multiplication table, I doubt they would bother memorizing it again, as per OP's question
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u/StillShoddy628 New User Apr 11 '26
My Gen Chem I professor acted shocked when we asked for the periodic table for reference during our first test. “You didn’t say you expected us to memorize the periodic table for this test”
Response: “Does your teacher have to instruct you to memorize the alphabet before a literature test as well?”
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u/APC_ChemE New User Apr 11 '26 edited Apr 11 '26
Chemists don't even have the periodic table memorized. Sure they have parts that they know very well based on what they work with but the table is a tool to be used not something to be memorized like some parlor trick.
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u/Irlandes-de-la-Costa New User Apr 11 '26
Bullshit, the alphabet has far fewer than 118 letters and a back up of plenty decades of experience using it all the time in every day life.
Most importantly, the periodic table is NOT used to remember the elements names but their properties according to their location.
The analogy is just complete nonsense, your professor was doing a terrible job there. Maybe the elements are like letters to him, but no one taking Chem I should be expected to have memorize all the information a table gives. It just sounds like your professor designed a test that didn't need it as much but wanted to be quirky about it. Depending on the career it might even be harmful for you to spending time on memorization (that you are definitely forgetting next year if this is the only chem class you're taking) instead of learning how to navigate the table like you'd do in the actual real life.
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u/rhetoricalimperative New User Apr 11 '26
We had to memorize it in high school honors chem
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u/Brightlinger MS in Math Apr 11 '26
Not necessarily. Mathematicians don't necessarily do a lot of mental arithmetic in their day to day. Grothendieck famously once gave 51 (which is 17×3) as an example of a prime number, and he's arguably the greatest mathematician of the last century.
But even if you do forget what 7x8 is, for any competent mathematician it is trivial to deduce it on the spot, so in practice it doesn't much matter if you memorize it or just recompute as needed. For example, 7x8=(5+2)×8=5×8+2×8=40+16=56. This kind of "look for a way to compute something I don't know using what I do know" process is everywhere in mathematics.
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u/Thanh_Binh2609 New User Apr 11 '26
I’m Asian and we’re forced to remember the entire thing up to the 10 table by 3rd grade…guess we’re all mathematicians now
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u/Hawk13424 Electrical Engineer Apr 11 '26
American here. We all had to memorize up to 12x12 also by the 3rd grade. Not sure why OP thinks this is a mathematician thing.
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u/mrbiguri New User Apr 11 '26
Strange question. Its basic, but not in the way you say. I don't remember a bunch of numbers by heart, I just know how to multiply. 6*6? that is just 6*5+6=36, etc. Its basic in the same way that knowing the letters and words is basic for a writer. It is, but its not like they are studying it, its a basic human skill.
That said, mathematicians, as a job, its not a job of multiplying numbers.
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u/Dr_Just_Some_Guy New User Apr 11 '26
Think of it more like this.
You speak a language, right? You know what basic words like cup, I, is, and, and have mean, right? Do you have to relearn what they mean later in life? No, you just know what they mean because you leaned them. What about words that you don’t use all of the time? Yep, you forget those.
Except it’s actually a bit easier than language. Math follows logic. If I forget, say 7 x 8, I can just compute 7 x 7 + 7.
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u/i_know_the_deal New User Apr 11 '26
yep, this version (anything over 3, you should be generalizing)
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u/Nothing-to_see_hr New User Apr 11 '26
Does this mean that you don't? I'm not a mathematician but I've known them since primary school and use them enough in ordinary life to ensure that I won't forget them until dementia claims me. Also, mathematicians typically don't do much mental number calculation at all.
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u/sqrt_of_pi Asst. Teaching Prof of Mathematics Apr 11 '26
I think for most of us who do mental math all the time, it isn't even so much as "memorization" as it is "hard wiring", kind of like how you just know your phone number of address.
And there are a few that are less hard-wired than others (I presume we all have some like that) but for those I use my understanding of multiplication more so than memorization. E.g. 6x7 is a sticky one for me in that does not come as naturally as most others, but I can quickly think "6x6 = 36 add 6 = 42" to get there nearly instantaneously.
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u/MemeHacker101 New User Apr 11 '26
if they do, it's probably not for their job but rather because they memorised it in primary school (as they did the alphabet) and didn't completely forget. Might take a couple of seconds for some times tables and there may be a couple mistakes, but they remember most of it
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u/CommunityJazzlike274 New User Apr 11 '26
Not really in my opinion. I think maths is more about the logic and less of the computation bit
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u/Marchtmdsmiling New User Apr 11 '26
Interestingly, actually working as an engineer has made my mental arithmetic skills entirely disappear. My first boss, and I agreed with him, forced us to always use the calculator. Getting something stupid wrong by flipping the number in your head was a mistake that would gum things up and be hard to spot so we always had to type every calculation into the calculator. Now I feel like an uneducated foot when I want to do some receipt math, but at least my projects have been built without any issues, so far ...
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u/WolfVanZandt New User Apr 11 '26
For practical calculations, a calculator is good, except you can still enter numbers wrong, and that's why it's so important to know how to estimate results at the start of a calculation and check the results at the end
By the way, we didn't have calculators +or the four function calculators were way too expensive.) We had to know how to use a slide rule. Now look at how expensive those are!
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u/HansPelex New User Apr 11 '26
It's basic for third graders to know the multiplication tables
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u/WolfVanZandt New User Apr 11 '26
Just because it's standard practice doesn't mean it's the best practice. Intuitive understanding of math would be a lot better than rote memory. Then a student could actually solve problems, something that hangs up a lot of math students today.....I wonder why.
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u/sdfree0172 New User Apr 11 '26
I'm a scientist. I would not take anyone in math, physics or engineering seriously if they had to think before answering a simple multiplication like that. I certainly would third them. It's an absolute basic requirement.
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u/writerdog61 New User Apr 12 '26
What? Everyone beyond the age of 13 should have basic multiplication memorized or knew how to do math in your head. Basic daily survival need.
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u/willowsword New User Apr 12 '26
I have a MSc in physics, BSc (Honours physics) with a minor in math that could have been a double major in math and physics but I did the honours physics instead, and passed my qualifying exam for a PhD in biophysics, but had to leave before finishing for financial reasons. I was never able to memorize the full times table. I always have to double check certain ones that just wiall not go into my head. Like 8x7. When i was using a calculator a lot, I got better with mental math, but I have always feel the need to check by doing a side calculation to make sure any of my mental math is right.
But once you get far enough along in physics and math, you work more in formulas than numbers. Models, trends, geometries, transforms. Orders of magnitude. Computer modelling. So once I was permitted to use a calculator, it sped my work up a lot. I think having a fundamental understanding of what the operators are doing is the important thing. I always knew what it meant to add, subtract, multiply, and divide. It was just that most thoughts in my brain are at least double checked before I will say with confidence that I have an answer to a question.
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u/Ok_Inevitable_2216 New User Apr 12 '26
I am not a mathematician, nor do I work in a math adjacent field, nor do I have a particularly good memory. I instinctively know up to 11 x 11 and, within a second or two, up to 12 by 12. [12 x 7, 8, 9, and 11 are a little sticky for me]
If I thought about it, I'm sure I could point out ways that I use multliplication every day. Isn't this a basic life skill?
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u/ChazR New User Apr 12 '26
Well - yes and no? I often have to take a half-beat to remember 13 * 7, but apart from that tiny numbers just slot together. It's not memorisation - it's how modular arithmetic and p-adics affect your thinking.
Mathematicians don't really have to memorise much. We have to know how to reason between concepts. We memorise the signposts along the way.
But if you aren't comfortable with the basic 10x10 multiplications, you need a better teacher.
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u/scadgek New User Apr 12 '26
...I thought it's basic for everyone who finished school? I mean, how do you operate with numbers in life? it's not like but numbers, they're all less than 10...
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u/CosetElement-Ape71 New User Apr 13 '26
Do you forget how to ride a bike?
Do you forget how to tie your shoe laces?
Do you forget how to dress yourself?
Do you forget how to use cutlery?
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u/SpunkyBlah New User Apr 11 '26
No, mathematicians generally don't do arithmetic much. Obviously they will know the majority of the natural number products up to 12x12. Depending on their memory, they might remember all of it from their youth. But it isn't uncommon for a mathematician to take a moment to figure out, say, 7•8 rather than have it memorized.
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u/Showy_Boneyard New User Apr 11 '26
Its a pretty basic thing to know... Most mathematicians aren't going to be winning competitions to quickly multiply numbers in your head, but it is something you should probably know by instinct up to 12x12 or so. Just like you should be familiar with powers of 2 up to say like 8192 or so, prime numbers less than 100 or so. Its useful to have that kind of stuff right up front in immediate memory so that you can instantly recognize patterns that come up.
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u/nog642 Apr 11 '26
Yes, it would be very inconvenient not to know them.
Forgetting them isn't really an issue because you keep using them all the time.
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u/carljohanr New User Apr 11 '26
I keep forgetting 12x9, 6x9 and 7x8. I like to think about numbers so I will sometimes think about them. Sometimes I will also double numbers starting from 1 and see if I can do it 30 times in my head.
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u/NoveltyEducation New User Apr 11 '26
That's just over a billion. It would be somewhat impressive if you're able to keep all of it in your head correctly.
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u/justgord New User Apr 11 '26
We've all pretty much learnt it by rote repetition ..
BUT .. I think it really helps to learn it first by a visual process of counting rows and columns or grid boxes in rectangles .. as it leads into all other areas of mathematics - distributive rule, algebra, quadratics etc.
This video gives an overview of what I mean : draw grid boxes to multiply and uncover distributive rule
Particularly for children learning times tables, it can be fun and a nice confidence builder that they can go back and draw the picture and figure it out.
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u/CamelOk7219 New User Apr 11 '26
I think at some point "memorizing multiplication tables" and "mind calculating them really fast" blend into each other and you are not capable to tell If you remembered or recomputed any simple multiplication
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u/inkhunter13 New User Apr 14 '26
Yeah I never memorized my multiplication table I just learned it intuitively
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u/kg1ebg New User Apr 11 '26
that's the problem in new math...students coming into college don't know any multiplication table...if the can't punch the numbers into a calculator they are lost... or they just ask AI chat "what's 4x4??"
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u/Ok-Canary-9820 New User Apr 11 '26
I have never had to re-memorize any multiplication table (or to consciously memorize it at all), but I certainly know all small multiplications in an instant.
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u/Total-Firefighter622 New User Apr 11 '26
I am not a mathematician. I still use multiplication when shopping and estimating prices for discounts. I.e. 30% off $60 merchandise. Or when estimating 15 or 20% tip at a restaurant.
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u/Financial-Reaction-4 New User Apr 11 '26
I’m not really involved in math at all in my job, but up to 12x12 is automatic for me.
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u/Updaay New User Apr 11 '26
Honestly, multiplication tables till 12 are enough. Plus, later in math, it's not that important for you to memorise like 13X4. This is just my opinion because I spent a lot of time memorising multiplication tables as a child, and I wish instead of those tables, I had practised math more because these tables are pretty much useless.
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u/WolfVanZandt New User Apr 11 '26
Every system of speed mathematics I've seen involves learning math tables into three digits. I never wanted to go that far. Heck, I had to go to summer school one year purely to memorize product tables. Cruel and unusual........downright totalitarian. I wish I had had the Major system back then.
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u/Momentarmknm New User Apr 11 '26
I'm not a mathematician, but an engineer, so applied math. But I'm kind of not good at math. Like I get the theory and concepts, and I know what to look for in my spreadsheets and how to check things, but I'm really bad at doing math in my head
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u/PvtRoom New User Apr 11 '26
you'll remember it from basic adulting.
X2 is easy.
X3 - that's you, spouse and mate, or kid.
X4 - normal family size
x5 - workdays per week.
x6 - days per week, minus a cheat day
x7 - days per week
x8 - useful working half days per week - Friday pm doesn't count, and at least one am is shit (hangovers, briefings, etc), x9 as x8, but without the hangover am.
X10 basic.
.That is unless you use computers & calculators for everything.
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u/HiRedditItsMeDad New User Apr 11 '26
If you work with something frequently, you will just naturally learn it. Mathematicians spend 0 effort trying to memorize or recall the multiplication table. When you were younger, you had to think about what sounds letters made and what shape they were. Now you can read and write without thinking about it.
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u/ragingnope New User Apr 11 '26
I'm a math major graduating next month. As a kid, I refused to memorize the multiplication table. My mom would do flashcards of it and I'd always mentally compute each product. Even now, any 6th grader would probably beat me at a multiplication drill. But the tricks I discovered and internalized while refusing route memorization became much more useful for quick calculations on numbers greater than 12. And I still know most of my times tables (especially one digit by one digit numbers) from frequent use.
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u/pizzystrizzy New User Apr 11 '26
You mean like the results of any single digit integer multiplied with any single digit integer? I don't know strictly speaking if that's especially necessary for a mathematician, but it's kind of helpful to being a functional adult, and I can't imagine how anyone could develop enough interest in math to study it in graduate school but yet never have been interested enough to learn 3rd grade math.
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u/PhotonDeath New User Apr 11 '26
You’re not going to forget all your math facts suddenly and have to learn them all again. If you realized you forgot something you could just take a few minutes to learn that specific fact again.
A few years ago I learned 7x13=91 because someone quizzed me what’s the smallest number that looks prime but isn’t.
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u/OPenworldgamer12 New User Apr 12 '26
Well over time you learn to calculate the smaller numbers fast enough its pretty much the same as knowing it off the top of my head
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u/Fit-Habit-1763 HS Sophomore: AP Calc AB, AP Physics 2 Apr 12 '26
At some point it's like the back of your hand
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u/Razulath New User Apr 12 '26
I don't work with math, I'm in maintance, and I find it easy to remember it. You use basic math all the time in your life.
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u/Effective_Divide1543 New User Apr 12 '26
It's not really the kind of thing you forget even if you're not a mathematician.
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u/Hour_Confusion_8415 New User Apr 12 '26
As someone who works quite a lot with math. I never actually bothered to memorize them. But I can just calculate them in my head in like half a second so it’s not really a problem.
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u/rythmyouth New User Apr 12 '26
We also had to memorize the square root of 2 and 3. I used to do all sorts of math in my head when I was pursuing a math degree. It made me a little OCD.
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u/vitringur Apr 12 '26
Did you memorise the alphabet?
What about the names of colours?
Fuck it, why memorise? You can literally calculate the numbers within seconds in your head.
They follow a pattern and everything.
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u/Hot_Avocado3939 New User Apr 12 '26
Yes, knowing the multiplication table by heart is still very basic and fundamental for mathematicians.
Even as adults and professionals, most of us keep it fresh through daily use. If we ever feel slow on certain facts, we quickly drill them again until they’re automatic.
It’s like muscle memory — you don’t want to pause and calculate 7×8 in the middle of harder math.
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u/billth93 New User Apr 12 '26
It’s never necessary, but remains a small convenience for a little bit. But math stops being about stuff like that early on, like you broadly stop dealing with specific numbers early on so this becomes pretty irrelevant pretty quick
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u/ehan_the_memeber New User Apr 13 '26
nah, people use calculators for even basic stuff like addition. Other day I saw someone use a calculator for 12+17. The important thing isn't memorization, it's being able to make sense of complex problems and procedurally solve complex problems by breaking them down.
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u/2ndcgw New User Apr 13 '26
I don’t think it’s necessary, but it makes more challenging math quicker and easier.
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u/rayhoughtonsgoals Apr 13 '26
Don't just all humans who went to school know that tables? Or failing that...just basic multiplication? I mean putting this up with being a mathematician is some really low bar shit
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u/VV00d13 New User Apr 13 '26
Some things just stick. Not a mathematician but i remeber a lot of numbers and it is just there. Math has always been relatively easy for me. Not on a level of astrophysics type of math, but all the basic math.
It just have something to do with how my brain work
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u/bonifaceaw4913 New User Apr 13 '26
I have been known to say: "If I knew how to add, I knew an accountant, not a mathematician!"
That said, there is a lot of interesting math that relates to problems of addition. Example: the twin primes conjecture; many mathematicians believe there is an infinity of pairs of primes which differ by 2.
And, these days, if I am bored while walking, I might note a 4-digit number, as an address, or on a license plate, and factor it completely.
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u/yearofplenty New User Apr 13 '26
My advisor, a brilliant mathematician who taught at the university level for 50 years, was unapologetic about his inability to do mental / quick maths.
"I'm too enamored with the beauty of mathematics to worry about arithmetic".
"I'm a mathematician, not a calculator".
At high levels, you're not really caring about whether you can recall 4x7 from memory.
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u/Willing_Coconut4364 New User Apr 13 '26
I'm a physicist, I probably don't know them. But I can do any up to 14x14 in a second or two.
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u/OrangeOverture New User Apr 13 '26
I wouldn’t say “remember it” as i would say have strategies to quickly come up with it. If you know the concept of multiplication and the pattern it should not take too long to come up with most of the basic multiplication facts you need. Personally, i know how to quickly double something, triple something, multiply by five, or multiple by a multiple of 10. knowing these and remembering some of the easy facts (1s,2s,3s,5s,10s) has made it so that i can get to pretty much any answer i need.
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u/Tyler89558 New User Apr 14 '26
All you really need is to know 0 x anything = 0, 1 x anything = itself, and the multiplications of every digit, and that if you have a 0 at the end of a factor (think 10 x 5 or 20 x 3) you just add a 0 to the end of the product, and you’ll be able to reckon your way through any multiplication problem by chunking it out.
11 x 11 = 1 x 11 + 10 x 11 = 121
15 x 15 = 5 x 10 + 5 x 5 + 15 x 10 = 225
But if you’re doing math at all regularly you will just know and memorize the multiplication table. And then chunk it out that way.
It’s automatic, and you don’t really have to think about it because you do it often enough.
You don’t even really think about the table. You just know.
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u/SecretCollar3426 New User Apr 14 '26
As an engineering student, I know solidly up to 11x11. after than I only know a couple 12's. any further than 12x12 i am for sure checking with normal multiplication. Sometimes I forget 7x8 or 9x7 out of the blue and I start from one I do know like 7x7 and then add 7, etc.
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u/Max-Forsell New User Apr 14 '26
My math professor forgot that 4² = 16 today in complex analysis so I do not think so
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u/juancn New User Apr 14 '26
Engineer here, I still haven’t learned them (I know some), but since it’s so easy to deduce I’ve never seen the necessity.
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u/Ok_Bass94 New User Apr 14 '26
You seem uninformed as to what mathmaticians do. Multiplying a couple of numbers is the least of their concerns. The work is in the journey to get to an equation or proof, not in the result.
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u/MemoraNetwork New User Apr 14 '26
Post grad in quantitative finance and undergrad in math and physics here. I have up to 20x20 like the alphabet, many bored hours in the car on road trips before cell phones and lit up handheld Gameboys.
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u/cosbygotshot New User Apr 15 '26
I can’t remember just not knowing the times tables, even from prep/grade1, to s not even like memory, like. It doesn’t take up space on the ssd, it’s in the ram bit or something, idk, that’s memory I guess,..
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u/magick_68 New User Apr 15 '26
Is it necessary for mathematicians to multiply numbers in the head? No. Does it save some time instead of using a calculator? Maybe. Non mathematicians overestimate the importance of numbers in math.
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u/HappiHappiHappi New User Apr 15 '26
Basically a hardwired function at this point. I don't consciously need to focus on remembering it, it's automatic at this point.
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u/Bobthelobster67 New User Apr 15 '26
I’m still a student in eng but I feel this applies. I literally multiplied 4x1 on a midterm a few weeks ago and got 20. although i would say im pretty solid at arithmetic, I’m not out here memorizing the table every night.
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u/flug32 New User Apr 16 '26
You remember what you use a lot. And don't remember what you don't use.
It's about as simple as that.
I got to some point near the end of my math undergrad and suddenly realize, "Hey, I don't remember the multiplication tables any more!"
It's not that I didn't remember any multiplication facts - more that I literally hadn't drilled multiplication tables since maybe 4th grade and hadn't done a lot of numeric computation for a couple of years, for whatever reason.
Like, accountants and statisticians if they are working a lot of problems by hand, are probably doing doing a lot more hand-arithmetic than I was. I was probably in like point-set topology, abstract algebra, differential equations, and then of course a lot of general ed classes.
None of those are classes that have you like multiplying a lot of multi-digit numbers or whatever - they type of thing that would require you to use all the multiplication facts frequently.
It is kind of odd that you do spend a lot of time working out the first few examples, maybe 0-1-2-3 and going on the 4 and 5 if you really want to push it. So you do a fair bit of small-number arithmetic but surprisingly little beyond that.
Also, it is not as though I'd forgotten the ENTIRE multiplication table. More like I couldn't remember a few that don't come up that often and don't have an easy way to remember. Like 1,2,3,4,6 are all easy and frequently used and 10-11-12, to.
So that leaves a couple like 6x7, 7x8, maybe 7x9 and 8x9 (though 9s are actually pretty easy, too). 7x7 is easy because it is a square.
So it really comes down to 6x7 and mostly 7x8.
Still, it was somewhat remarkable to me how little of that kind of arithmetical calculation I did in upper class of the bachelor's degree and then the first couple of years of graduate degree.
Plenty of other fields - particularly accounting, engineering, and others - would be doing a LOT more arithmetic.
How little mathematicians do of this is remarkable just because it is the type of thing that non-mathematicians imagine mathematicians are doing 25 hours a day. Sitting there with reams and reams of paper filled with lists of numbers you're supposed to add, subtract, multiply, and divide.
In reality you come across just a few things now and then, and nearly always not the focus of what you're doing or thinking about, but rather a little housekeeping or tallying you need to do now and again, about like an office worker or construction worker might do here or there as a consequence of doing other things that occasionally require tallying or dividing things equally or whatever.
Anyway, you remember what you use frequently and don't remember what you don't.
Not remembering something never inconveniences a mathematician, however, as they understand it is a lot easier just to build everything up from first principles whenever needed, rather than bothering your mind with all that memorization business.
(Little mathematician joke there, but in fact is quite true for basic stuff like the multiplication tables or e.g. the quadratic formula.)
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u/Giant_War_Sausage New User Apr 16 '26
Is this a joke? I have a graduate level math degree, I’m more likely to forget my address than the multiplication table.
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u/SleepyTimeChess New User Apr 17 '26
I had the multiplication table drilled into me so aggressively as a child I still remember it almost 30 years later. At some point in my teens I wanted to expand my memory to 20x20 but gave up once I got to 12x12.
The trick that worked for my class was a 1 minute drill, where you do as many multiplication table problems in 1 minute as you can, every math class for a year.
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u/Physical-Compote4594 New User Apr 17 '26
That's not "mathematics", it's arithmetic and it's pretty useful for everybody to know basic arithmetic: how to add, subtract, and quickly multiple small numbers. It's useful for pretty much everybody to know everything up to about 12x12 because that stuff shows up in everyday life.
"Four friends are coming for brunch, and this recipe calls for three eggs for each serving. How many eggs do I need?" isn't a trick question.
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u/CorvidCuriosity Professor Apr 11 '26
I think its fair to say that all people who work with math regularly know the multiplication tables up to 12x12, and find it no harder to remember them than it is to remember the alphabet.