Little brother's homework. Can't figure it out and I'm feeling dumb. (Reddit r/Homeworkhelp) 

Wow, very nice!!

6) Let aₙ be the sequence of numbers concatenated from each row(a₁ = 1, a₂ = 11 a₃= 21 a₄ = 1211, &c.). Prove that the limit of the ratio of a term of the sequence given and the previous one is a solution of a polynomial of degree 71.

7. What will happened if we add an imaginary number (to the question)? What will happened to the rest of the answer, I wonder how it would look like.

Wth is this comment saying I don't understand 😢

How about you prove god isnt real

Depending on the age. The point of number puzzles isnt really that we want these young kids to think this is math but instead to get them to strategize how they approach. I thought that algerbra was really REALLY hard in school and was scared of it when I was in 4th grade knowing it started the next year (not looking forward to college as I am trying to atend this coming semester and I barely passed algerbra 1 and graduated early circumventing my need for algerbra 2) but when i learned pre-algerbra and understood that its really just repeating what I already learned I wasnt as scared. The same goes for a puzzle like this. If I see a question and it needs me to work backwards from the answer i need to develope a strategy to do so, and thats the primary goal of this exercise. Make a child say the problem out loud and the solution becomes obvious and they feel more confident

This is no more math than the sequence "1, 4, 3, 11, 15, 13, 17..." is. For those curious, n is equal to the number of letters in that sequence. It is an ENGLISH puzzle, not a math puzzle.

​​@@tristanmitchell1242the sequence in the video requires no reliance on the English language though. It can be denoted formally, and in a way that gives you the same sequence even in a non-decimal number system, but it is just much simpler to intuit the sequence than denote it in the formal way. At a third grade level this is math because it's counting characters, and at a high level this is a complex sequence that can be denoted recursively

This is not math, per se, but it is a logic puzzle using numbers. I remember being chosen to participate in a group that explored various math-adjacent subjects including logic puzzles like this when I was in eighth grade in the late 1970s.

I'd say it is math. It's run-length encoding, something used in data compression. Except the first line, each one is a run-length encoded version of the previous, each a length-symbol pair. It's not tied to English or any language.

came here to say exactly this after seeing the thumbnail

A nice riddle at that

​@@arikrex9978from which POV that this one is nice? I like riddled but this kind of problem is ridiculous. Tried to trick you into math problem, but nothing mathematical in the end

We don't know the full context, the person who put it on Reddit called it "math homework" but the problem above it looks like a puzzle too. It's a grid of random numbers, not a sudoku but looks similar. So this may have been an assignment about puzzles or riddles, it's not entirely clear.

@@Phyrre56 i mean even sudoku has computeable algorithm to solve. This one....nope

Like you said, great as a tool. Just introducing kids or anyone to this would teach them something about thinking a bit broader for deceptive riddles such as this, but slapping it on homework or a test in the context of a math class where you're solving mathematical sequences that are presented in this exact same way is just ridiculous. This is something that should be taught, not challenged.

This is not something which a 3rd grader can solve at all, only 8 graders or later can understand and solve it in my opinion

@@NarutoUzumaki-gk5yv I really don't know why you would think that. There isn't any complicated math to it, just some creative thinking. Kids can solve puzzles like this very early on, especially if they've been exposed to similar "outside the box" thinking problems before. A kid in elementary certainly shouldn't be EXPECTED to solve this problem, but some will be able to. Heck, a high schooler shouldn't be expected to solve a problem such as this. As long as it isn't graded for correctness, it's a very fun problem to discuss with students. Seeing other people come to the realization as you read it out emphasizing each pair of numbers is pretty satisfying too

This is the main issue with modern teaching in schools. Teachers try to bring unrelated things into irrelevant topics and expect children to "get it via the power of their imaginations", only to have such openness in such stakes can put children into a choice paralysis when they didn't ask to. It's just like Rainbow Words (IE: draw lines around a random word, in English class), poorly implemented and poorly presented. It's like they're forcing us to figure out if Schroeder's Cat is alive or not, and the students are stuck arguing with "Yes" or "No", then the teacher gets angry enough to spend the rest of the class session lecturing about how THEIR answer is more correct.

@@NobodyAsked-xh8cs Well, keep in mind that a lot of these "look at my kid's ridiculous homework" things are not really as ridiculous as they seem and are actually just because the parent wasn't actually in class with them and so may not have the same context. The homework doesn't necessarily _say_ this is supposed to be a math problem (that may have just been a wrong assumption on the parent's part), and this sort of problem is probably a whole lot easier to figure out if it's something they just explained that day in class (so it's fresh in the kid's brain, at least if they were actually paying attention). In that situation, there may be nothing wrong with it at all, and it's really just because of the parent's own ignorance of what the actual class material is that day, nothing else..

It's a good exercise in having to figure out what kind of task you're doing though

When he said "read it out loud" I'm like, okay, but it's still "1 | 1, 1 | 2 1..." because i didn't interpret that as 'list the contents of the box as if putting it in a sentence' so i just read the box contents separately and understood nothing.

@@shirothefish9688 same here.

​@@shirothefish9688 well, now you know such trick exists. So will try it next time you encounter it (i assume).

@@DimkaTsv hopefully.

those puzzle games give me so much headaches 😭

I was just thinking that this is like amateur hour cryptography or a headscratcher that someone would have brought to Sherlock Holmes who would then dismiss them as an incompetent because they didn't immediately see through the lie that what was presented as mathematics was actually a fragging word puzzle.

It does actually. It's a puzzle in Please Don't Touch Anything iirc

@@mahdi9064 LOL The worst part is these kinds of puzzles are usually in action/adventure/RPG's

This is known as a term rewriting system. It's half-way between mathematics and computer science

Same here I also thought that was fibbonaci

It's third grade math dude. There is no way it is the Fibonacci sequence

@@sharpasacueball Pffft. Kids just need to 'git gud' 🙃

​@@sharpasacueball The Fibonacci Sequence is just addition. It is 3rd grade math at the highest.

@@sharpasacueballyou don’t need to be a genius to be able to add the last 2 numbers together

Hey i got this question Find the sum of all the coeffient of multiple of 3 exponent of (1+x^2-x^3+x^4)^10. Like the coeffient of x^3 + the coeffient of x^6 + the coeffient of x^9... Could you help me?

Explore ðe Pascal triangle @Guzzinhu

it makes sense that there can only be 1, 2, and 3, because the pattern 33 could only come from another 33, meaning it is impossible to get two or more 3s in a row

120th like! :3

Couldn’t a 33 be made by one 3 and three 1s or 2s?

@@forbidden-cyrillic-handleis it 31, isn’t that the problem where you add n bisecting chords on a circle and count the subsequent number of segments? But yeah, I get your point. It really depends on the problem.

​​@@forbidden-cyrillic-handleI get what your saying, but those "guess the next number in the sequence" questions are usually made for kids. Meaning, they're definitely not asking to find a polynomial that fits the sequence. And let me tell ya, when presented with such questions I'd still try with the simple method of doing sums, products, differences or divisions between known consecutive elements of the sequence. TLDR: given that infinite solutions to these problems exist, the correct one is most likely the easiest one.

@@forbidden-cyrillic-handle I agree, it wouldn't be okay to grade such problems.

@rosskrt it might be ok to have the students provide a formula that explains their choice for the next number, although that probably would be out of scope for many students around this level.

@@forbidden-cyrillic-handle That type of situation is solved by framing the questions in relation to the current methods being taught. Any answer that is given that doesn't use the method the test is testing for should be disregarded. In real world there are 'most correct' answers, like all the negative answers to anything regarding a distance of something, there is no negative distance so while a negative result can be a mathematically correct solution to the equation, its fully disregarded because of the context. Given the context here of it being for the 3rd grade, we can throw out any rigorous method like being the bisecting chords, the answer on a 3rd grade assignment for your proposed problem is 32, end of story. It literally doesn't matter what it could be, its applying the lessons you are being actively taught to the problem in front of you.

Out of curiosity, what is your native language?

@@metroplexprime9901 hebrew

​@@slkjvlkfsvnlsdfhgdght5447 Interesting. The little language goblin that made a conlang always likes collecting tidbits about other languages.

@@metroplexprime9901 what's the language you invented?

@@slkjvlkfsvnlsdfhgdght5447 is it similar to what we have in Arabic where you have the dual form? So instead of saying 2 2s you'd say 2 in the dual

We actually did have quite a bit of stuff like that in our exercise books, but it was private school with side step from governmental lessons plan It was quite nice if you knew your child would grow and go study in math university lol, but apparently not everyone in class enjoyed this idea

@@Airin258 yeah I suppose that makes sense.

These days schools and teachers can't actually tell the difference. As far they know this IS maths.

I remember this problem when I was in school, but I live in Europe so idk

Nah, it isnt math, its logic. By categorizing it as `math`, you load up the part of your brain that adds, subtracts, multiplies, so on. Not the part that solves matchstick puzzles (like the ones where numbers are written in matchsticks and you need to re-arange them to write a correct equation). A kid doesnt know fibonacci or anythin else, its gonna say these aloud and then go from there. Its like being cursed with knowledge, same with those attention span videos on youtube. By giving you an incorrect framing, they force the brain to "optimize" out the wrong things. In fact, thats the basis of most illusions.

What did you learn by solving this though

You learn how easy it is to...something.

@@sasho_b. This isn't logic; it is a riddle. We shouldn't be testing children on their ability to solve riddles. We shouldn't ever be testing anyone on their ability to solve riddles except in riddle solving classes and competitions.

@@sasho_b. It's not just about knowledge but also about counting a certain way. Does every child think like "there's one one, then two ones, then one two and one one etc"? Because as an adult I count them simply as one, one, one, two, one etc.

literally

3rd Grade Grammar then.

A formal grammar is a mathematical object though.

Then you’ll have people after seeing this say, See this is stupid. This why American school kids are stupid because they’re teaching this in 3rd grade!

as someone who's interested in compiling programming languages, grammar can be math sometimes 👀

this ain't math this is meth

I mean, it's related to math, it's just not something that they should give as math homework, or teach in math class, since it's not teaching anything related to math, or proving that you know anything about maths.

@@Acuas It should be on a test or homework only as extra credit.

@@Acuas having numbers in it doesn't make it related to math. this is just a word puzzle, its like giving someone wordle for homework.

@@PandaMan02 to the contrary, not having arithmetic in it does not make it not maths

This is where being an external processor comes in handy lol. I had that "everything clicked" moment too but because I read it out loud to myself to help process it better😅

@@J75Pootleexternal processor?

@@anironfarm6056 I think that's what it's called? I'm someone who quite often needs to say things out loud or write them down etc in order to better process the information (I'm better at processing things "externally" rather than just "internally" in my brain), this can lead to me talking to myself a lot. For example, if I'm doing a menial task like putting the dishes away then I sometimes get stuck in my own thoughts and forget what I'm doing, but if I say to myself "what am I doing? Where does this go?" then I'll almost certainly remember "oh, of course, it goes in that cupboard" and then off I go to that cupboard.

same. It was really simple once I realized that (but, as other people have stated, NOT MATH) but getting there in the first place was rough, because I was expecting it to be something... even SLIGHTLY useful?

Ikr?! He is so good!

a prgrammer would've easily solved it, if he knew it was meant for him. they always do such silly things as adding information about the sequence into the sequence as apart of it.

It's pattern matching, which is reasonable for a third grade puzzle.

@@jeffwells641 what would i know, i've never been a 3rd grader myself

@@suyunbek1399Don't worry, I believe you can achieve anything if you work hard enough, and you keep your expectations low enough.

I read somewhere that kids have a much easier time figuring it out than adults because they don’t overthink it. The adult brain conceptualizes numbers more holistically and is trained to think about them in terms of discreet patterns and how they represent real world problems. Kids look at them like they’re completely devoid of meaning like a color. They’re more prone to start trying to solve by look and say because they don’t immediately assign abstract concepts to the numbers.

If you go to math competitions at a higher level, you see lots of problems that are similarly "lateral thinking". The branch is called combinatorics. As someone who competed in the top 30 US students in highschool, I can say that the pattern we see here could easily be something we'd analyze in a competition. As another example, in our math competition summer camp we had a day on "hat problems", which were logic problems that sound like "if infinite people are in a line and they each see the color of the hat of the person in front of them..." etc. Basically, math doesn't have to look like what most people associate with math.

​@Benw8888 yeah, pretty certain I did something similar last semester in my college math class. As a math major this isn't strange

The 2 ppl replying @pdw1230 and @Benw8888 are completely missing the point. It doesn’t matter if you’re able to solve this in college or a high level competition…. Because this question was given to 3RD GRADERS. This is the equivalent of tossing a baby into water expecting it to swim because *you* have the ability to. It ain’t gonna happen.

@jblockminermc5401 I'm just saying it's used in math. Is it fair to give a 3rd grader? I don't know. It is just pattern recognition though

@@jblockminermc5401 I assure you that there are third graders already competing in math competitions and winning. So you saying "it ain't gonna happen" is just you underestimating children's intelligence. Again, not saying this problem should be given to every 3rd grader. But it's fine for the top ones who are pushing for something greater.

this also manages to show why compressing a compressed file will always* cause it to increase in size *unless the compression algorithm is useless and only compresses the data partially

You mean like file compression? Seems pretty interesting. Please can you tell me more about this algorithm or tell me it's name so i can read more about it? It makes sense to write the number of ones and zeroes. And someone said it shows that compressing a compressed file will always increase its size, which is even more interesting.

@@chri-k Saving this

​@@tejasgupta1176 Yes! It's called Run Length Encoding (RLE). In information theory, encoding and compression are important because you'll come across the question, "how much data do I REALLY have in this many words". RLE is great for large groups of repeating data. A good example is the early pokemon games, where the sprite images were stored in how many black and how many white pixels were: BBBBBBBBBB BBUUBBBUUB BBUUBBBUUB BBUUUUUUUB BBUUUUUUUB BBBBBBBBBB imagine this "u" drawing. So er it would be like 10 B 2B 2U 3B 2U 1B 2B 2U 3B 2U 1B 2B 7U 1B 2B 7U 1B 10B But you can compress further (state the width so no need manual new lines) 10W 12B 2U 3B 2U 3B 2U 3B 2U 3B 7U 3B 7U 11B Further: don't even specify black or white, let the "parity" index do it. (ie the 2nd, 4th, 6th, etc is one colour and it alternates) 10WB 12 2 3 2 3 2 3 2 3 7 3 7 11 Then maybe you can repeat this if you want but you must consider 2 things: - it becomes more complex and you will end up with people in the comments complaining it isn't maths - redundancy in both human linguistics and info theory are impt in error correction and more compression means more need for error correction or risk corrupting the data 10WB 12 4 ( 2 3 ) 7 3 7 11 You might even overdo it and wonder if you've hit the limit This is actually worse: 10WB 12 4 ( 2 3 ) 2 ( 7 3 ) 0 8 Than this: 10WB 12 4 ( 2 3 ) 7 3 7 11 Which is actually what the video unknowingly hints! 1 1 1 1 1 1 1 1 4 7 7 7 7, 8 1 1 4 4 7, 1 8 2 1 2 4 1 7, 1 1 1 8 1 2 1 1 1 2 1 4 1 1 1 7, 3 1 1 8 1 1 1 2 3 1 1 2 1 4 3 1 1 7 Notice how the first line was compressed from 13 to 6. But then it went to 8, then 16 and 18 So the worse case when it's dense is 2 times original length, but best case is just 2 numbers. (you ever wondered why IT is INFORMATION technology? Now you know why, because information theory / how we convert, store, process, transfer, protect, and correct data was the basis of IT in the 40s US navy - the complement is computing - literally how to calculate. It's really how we manage to re-represent problems in different ways so that we can use the tools we have to calculate and arrive to solutions)

They probably exploded since I don't remember this puzzle, even if I did I'm definitely too dumb to solve it

that's.. kind of brutal

weird flex but lethal and successful

​​@@Artemi22 If you're playing a female character, the man hits on you both before and after this (assuming you talk to him before). Despite still being married, and after the trap is sprung, he's aware his wife is trying to kill him for his infidelity. (I think he did even WHILE you're solving the puzzle, but it's been a while and I don't remember.) Still brutal, but frankly, it's probably not the last time a woman is going to try to kill this guy. (EDIT: I forgot that you can kill the guy, either intentionally or just by failing the puzzle too many times, so it technically can be the last time someone tries....)

Honestly you can be too smart to solve it too.

Part of why I always hated sequence questions

I agree with you. I don't like "complete the sequences" because of this.

I love questions like this. I love riddles. If someone put this on my math homework I would be furious. You may as well ask people to translate a sentence into French while you’re at it; that has as much to do with math as this sequence does.

"IQ measures the ability to fill an IQ test"

"complete the sequence and prove that you used the simplest possible series to do so" would make it skyrocket in difficulty. How sure would you be that 1,2,4,8 can't be done even more simply than doubling the last? Sure enough to prove it without the slightest problem?

This is a language puzzle falsely titled as math

​@@dark6.6E-34It is. It's a sequence of sequences that you obtained by compressing the previous sequence in a relatively naive way.

Exactly, I not only think it's wrong to mark such a problem as math but actually harmful. A 3rd grader will infer that anything is math as long as it contains digits. If this was simply marked as a logic puzzle I'd have no problem with it.

it’s reddit where everything is presented as real to get karma

Math and logic go hand in hand. it's problem solving skills that will help people think outside the box.

If you go to math competitions at a higher level, you see lots of problems that are similarly "lateral thinking". The branch is called combinatorics. As someone who competed in the top 30 US students in highschool, I can say that the pattern we see here could easily be something we analyze. Just asking someone to recognize the pattern is a little silly, but analyzing properties of this sequence is undeniably math. Even just being asked to recognize the pattern trains pathways in the brain that would be helpful for combinatorics problems.

Step 1: Identify the problem. 99% will go for math-problem, apply the known math-problem solving paths and PROVE IT IS NOT a math-problem.

This isn't logic either. Logic follows strict rules. This is a knowledge problem. Either you've seen it before or you haven't.

It's exactly run-length encoding iterated with a starting input of 1.

This shouldn’t be taught for school unless someone is going into that field in the future.

@@zerotodona1495 studying math at a more rigorous level leads people to be stronger coders, mathematicians, physicists, scientists, etc. If the kid/parent wants them to be strongly competent in the future, and knowingly signed up for rigorous education, then this totally makes sense to be given to strengthen creativity and affinity for combinatorics.

Complete the sequence: 1 2 4 8 16... The next number is 31 and then it's one in the thousands... This is annoying because you might have found a rule that fits the set but of course it's "wrong". 6 7 9 8 6 8 6 6 What's the rule here? 😅

I don't know how you can say that sequences have previous little to do with math. This is just one example of a sequence that is very difficult to denote formally, while being very simple to explain intuitively.

@@elijahbuscho7715Suppose I give you the sequence "1, 2, 3". What comes next? Depends entirely on the rules I have in mind, which can be as complex or as simple as I like. All you can really do is you have found a POSSIBLE set of rules, and by following those rules you have chosen, the next value would be whatever. The next number is "5" incidentally, because the rule is that it has to match that one bit from "The Logical Song" by Supertramp.

@@kingbeauregard sure, but the sequence presented in the video is recursive and infinite and understandable without needing to look at any other thing, 3 things that distinguish it from your example

@@elijahbuscho7715 Okay then, the next value is 5 because I'm listing non-composite numbers. So we still have two equally plausible sets of rules and therefore two equally valid solutions. I can also make the next value 6, because they're solutions to the equation y = x^3 / 3 - 2x^2 + 14x / 3 - 2. That's a third perfectly valid answer.

Logic puzzle

@@bestaround3323 Which should not be part of a math test.

Math is pattern recognition analysis. This is pattern recognition analysis.

It aint a stupid gimmicky puzzle, its a demonstration of how perspective matters, and it being in math homework teaches a VERY important lesson, think outside the box. Dont just look at things from one angle. heres hoping thats how the teacher framed it and didnt just slap it on seeing the numbers...

@@JonO387 Logic is an important skill when you're trying to learn mathematics. If you can't solve this puzzle you may be too narrowminded to solve mathematic equations.

That's where I first saw it. Had me stumped for years.

Thanks!!

Next is... 31,131,211,131,221 There is also 1321-

and the 3rd graders can either fail or be sent to university

​@@allylilith5605loool

It's the same in any language

Well, in the thumbnail you can see the homework assignment is in Portuguese.

Look up the "look and say" sequence Not only is this math, but its famous too.

Man, I fucking hate subnetting. Such a dumb system setup in the stupidest way possible, and we're not using way better systems because reasons.

sameeee

ಠ⁠_⁠ʖ⁠ಠ

My stroke is having a brain

not-math problems disguised as math. I think the teacher may have had a laugh on this one, but it's not education at all let alone math education.

@@stephenwithaph1566 exactly this ain't math but some IQ test shit😂😂

@@stephenwithaph1566 I went to a catholic grade school. My teachers weren't really teachers. All the class and homework was predesigned by some company or another, but still, it was this type of work that kept me from getting other homework done.

​@@stephenwithaph1566 yeah, because apparently frustrating the student for fun and no actual educational value is "education" now. What bollocks

Pattern recognition and interpretation is a math skill and a valuable skill to have, but referring to this particular problem as a math problem is bad. This is a language puzzle, not a math puzzle.

B

B lol

16^8

sqrt(16^16)=sqrt(16)^16=4^16

16^4

Technically you count amount of repetitions a number has in sequence and write it so it's not about grammar and can work in any language. It's not Math task though. A logical thinking challenge, a puzzle, a general thinking test - yes, sure. But calling it a Math problem is misleading.

There’s even a wiki page about this. en.m.wikipedia.org/wiki/Look-and-say_sequence

It's not.

How is it not math?

The answer relies on the verbal expression of the numbers, not on any calculable pattern in the numbers themselves.@@globglogabgalabyeast6611

​@@globglogabgalabyeast6611just because it has numbers it doesn't mean it's math. it's a shitty puzzle

Isnt it the other way round here?

Its a puzzle. Encourages out of box thinking etc.