Adults baffled by simple exam question

[@mc576speedcubing]

I spent 30 seconds doing this in my head. Honestly, the hardest part of word problems is reading and understanding the problem itself. Edit: 150+ likes?? Thanks everyone!

[@skylark.kraken]

Yeah, I didn't catch "remaining" when reading the thumbnail, but easy solve once I saw that. I have a feeling that when I was in primary school key words like that would be underlined so it's hard to miss, you can't give a kid all of that text as it all hinges on a single word

[@nmappraiser9926]

That's very true. Just like in the real world, numbers are not picked out of nowhere, they are attached to real things, and the hardest part is assigning the numbers to real quantities and coming up with a meaningful answer from those conditions.

[@timeonly1401]

You are right: READING a question is the true key to doing word problems. Help students all the time, and I daresay whenever a student has a serious issue, it's because they didn't read and understand the problem. 👍

[@briant7265]

@nmappraiser9926 Plus the real world seldom lays out all the details in a well-formulated word problem. A real-world word problem would be like, "Your back fence needs to be replaced. It is 6' tall and 90' long, and made from dogeared cedar boards. How much will it cost?" You can't put that on a test, but that's how they come IRL.

[@resir9807]

That's why it's a crime how little value the math curriculum (at least in my country, Austria) places on mathematical modeling. The way you solve any real life math problem is first modeling it in a formal system (like algebra), then solving it in that system according to its rules, then interpreting the formal answer into a real life answer. Exactly the second part seems to be the only one the curriculum is interested in, when it is entirely useless without the others.

[@tribble1]

Fractions are like kryptonite for some people.

[@luisfilipe2023]

I genuinely don’t understand how people go on living adult lives without understanding basic concepts about fractions. It’s one of the few things from math class I actually regularly use even as a non math person

[@luccafortestoledo1300]

Did you know? 4 out of 3 people don't understand fractions

[@kinpatu]

Most people couldn’t count change from a $5 bill on a $3.77 purchase without a machine telling them the number.

[@TheGargantuanLeviathan]

​@@luisfilipe2023 Its just hard to understand ok. I can't explain why, but fractions are just hard to understand.

[@MrMayhem010]

​@@luccafortestoledo1300116% of people would say that you're wrong

[@ArchHippy]

It genuinely took me longer to understand the question than it took me to answer it.

[@anthonydamato5438]

Facts 😂

[@dunerable]

nothing hard about the question

[@meinacco]

Had to read it twice as well cause i thought there was information missing.

[@wallydraigle5382]

@@meinacco Yeah, I went in with the expectation of it being hard and kept thinking I missed something.

[@matthewmartinez3550]

@@dunerable When I first read it, I thought it wanted remaining pages, and it had missing info. The question isn't hard, but that doesn't mean it's not normal to have problems understanding them. That's why schools teach word problems to begin with. Much easier to solve a given equation than to figure out what equation you need to solve the problem.

[@Pendergast891]

My brain went to '30 + 1/8P = 3/4P' and solved from there.

[@DeathmetalChad]

same, right? Nerds unite.

[@sillyblizlele]

True, I just did 3/4P - 1/8P = 30 or 5/8P and did it easily

[@tiagoveiga]

Mine too

[@forgmanguy]

@@DeathmetalChadsince when did you have to be a nerd to answer an easy math question

[@steffenbendel6031]

@@forgmanguy Since society accepted "normal people = hate math"

[@maximepaccalet4449]

Although the book is quite short, the beginning shows a lot of promise and it seems like you can't put it down, but after the 5/8 mark, unfortunately, it turns into a slog.

[@pablorosada9788]

I mean seriously, if you can blitz through 30 pages in a day but then you need full day to make it through 6 pages and another full day to push through the final 12, the ending must be AWFUL.

[@inordinate_15]

Or simply no motivation​ to read on those days probably? @@pablorosada9788

[@asdbanz316]

@@pablorosada9788 who said Klein spent entire 3rd day on the rest 12 pages tho?

[@pablorosada9788]

@@asdbanz316 1/4 48 is 12

[@Qermaq]

That's when the book starts using formulas.

[@neochrispogi]

1/8 + 1/4 = 3/8, 1-3/8 = 5/8, so 30 pages is 5/8 [of the book]. From there, I just divided 30 by 5 to get 1/8 of the book and multiplied by 8. Took a minute to solve

[@MrMayhem010]

That was my exact thought process

[@bubtb-yl8lu]

Not everyone is as smart as you.

[@Battlekaik5]

You would get 48 pages. If 30 is 5/8 of the book, then 1/8 of the book is 6. I added 30 and 6, and then 12 to get 48. I know I was in the AGP program in 5th grade, but I don't think a regular 5th grader would be able to do this. It took me about a minute to do this as a HS Sophmore. Whatever the kids are learning today is rather unnecessarily complicated.

[@mariongordon4199]

YES! At 66yo that's exactly how I did it, and I'm pretty sure we were solving similar problems in that way when I was 10yo. As another commentator has said, people are making primary school maths look far more complicated than it needs to be.

[@obliviouz]

You didn't give the answer, zero marks.

[@HHuynh-DP]

Parents thought they escaped homework once they became adults. But like a horror movie, it follows them all through their lives.

[@stuartmcconnachie]

And all because they didn’t understand 1 + 1 = 3.

[@shinjonmal8936]

​@@stuartmcconnachie all because they didn't memorise the tables of 7

[@beauthestdane]

I mean, it's a trivial problem to solve, but probably not so much for that age group. I quickly did it in my head to arrive at 48 pages.

[@beauthestdane]

I did make the unstated assumption that he started reading the book on Monday.

[@beauthestdane]

At my age, I did it the "old way".

[@shubhamdwivedi1432]

Same here. It hardly took me 2 minutes to calculate while sitting on my toilet seat. I was suprised and opened the video link simply to check what is so challenging about it.

[@beauthestdane]

@@shubhamdwivedi1432 Yep, did the same.

[@robertveith6383]

​@@shubhamdwivedi1432 -- I don't give a *crap* that you did it sitting on your toilet seat.

[@luisfilipe2023]

Seriously why do people always have to be surprised by simple concepts???? Math literacy is in the gutter it seems

[@TheGargantuanLeviathan]

For me its like this: concepts like square roots, prime numbers, fractions and long division I literally do not understand. But when it comes to googology I DO understand it. I guess it depends on what you are most interested in. Also, me doing algebra is like godzilla in his most powerful form vs a coughing baby.

[@Patrik6920]

the main reason i belive is when mixed units are presented (as in us) wich adds an extra layer of complexity 1/5 inch + 1/8 feet + 1/35 yard = ?? ofc the solution is to convert everything to a common factor 1 yard = 3 feet = 36 inch -> 1/5 + 12/8 + 36/35 inch -> 1/5 + ( (12*35) / (8 * 35) ) + ( (36 * 8) / (35 *8) -> 1/5 + 420/280 + 288/280 -> 280/1400 + 2100/1400 + 1440/1400 -> (280+2100+1440)/1400 -> 3820/1400 = 382/140 = 191/70 = 2 + 51/70 inch OR 2 + 5/7 + 1/70 inch This is the primary reason US students struggle so much .. and even scientists actually has to work with this nightmare of a system called imperial-/customary-/freedom- units curiosa: 19028/7000 is aproximately equal to e

[@Zhiroc]

Eh, I learned the "old way", which is Algebra I for me, in 9th grade in... 1973? And there a lot of people in my class (the college prep course) who had lots of trouble with word problems. These were considered the hardest part of the class, at least to them. So I wouldn't be quite so quick to say that this demonstrates anything (though I think there is a strong likelihood that math and science skills are lessening).

[@mrosskne]

​@@Patrik6920what do you mean, struggle? fractions are easy to work with, certainly far more so than decimals. i always convert to fractions when doing mental math.

[@tharunsankar4926]

No it’s because it’s worded in a very wrong way

[@BossRoss13]

1:04 if it's not stated, then it didn't happen. Just focus only on the given information.

[@DavidZ4-gg3dm]

The question is badly worded. It should say that Klein began reading the book on Monday. If someone told you they read two chapters of a book yesterday, you can't assume they started reading it yesterday & those were the first two.

[@PlasteredDragon]

30 pages + 1/4 of the book + 1/8 of the book = whole book 30 pages + 3/8 of the book = whole book 30 pages = whole book - 3/8 of the book 30 pages = 5/8 of the book So if N is the number of pages then: 30 = N * (5/8) , divide both sides by 5/8 to get N by itself. 30 / (5/8) = N, dividing by a fraction is the same as multiplying by its reciprocal, so: 30 x (8/5) = N, so: 240 / 5 = N, so: 48 = N. There are 48 pages in the book. Double checking against the problem, 1/8 of 48 is 6, and 1/4 of 48 is 12. 30 + 6 + 12 = 48. Everything checks out.

[@lugiagaurdien773]

I keep losing hope everytime I see questions like this that adults can't solve

[@将軍九八.彁]

I don't understand. This is not a hard question. The real question is who reads 62.5% of a book before setting it down.

[@Davorox1]

He got distracted or bored 😅

[@whiterosesalchemist]

They had him in the first half

[@kenmore01]

I guess that depends on how mind numbingly boring it is. Maybe that's his best effort. I have been there.

[@petraderuiter3355]

His Mum called him for dinner, or it was light out.

[@jayfredrickson8632]

Me? Except I wouldn't put it down till finished 😅

[@chris_share]

I did it the "old way" in my head, by working out 8/5 of 30 - simple!

[@WhiteGandalfs]

It's solvable in the head in mere seconds. Simple, straightforward fractional arithmetic. What the heck are they talking about?

[@Gideon_Judges6]

I got 48 in my head. p=number of pages in the book p=30+(1/8)p+(1/4)p p=30+(1/8)p+(2/8)p p=30+(3/8)p p-(3/8)p=30 p(1-3/8)=30 p(5/8)=30 p=(30/5)*8 p=(6)*8 p=48

[@TheResidentSkeptic]

Yikes, overly complicated (or should I say simplified?) I just saw 30 + 1/8 = 3/4 = 6/8, therefore 30/5 = # of pages in 1/8 (which is 6), then 6 * 8 = 48. Guess I'll finish watching to see Presh's derivation.

[@neochrispogi]

I also had this thought process.

[@pijanV2]

everyone did, i dont know why presh keeps giving such easy problems

[@asuspiciousavocado3317]

​@@TheResidentSkeptic Same as me, but we both basically did the same thing as the OP. We just started "writing" or "solving" it a few steps already down the road. Technically the teacher wants the students to start from "1/4p + 1/8p + 30 p" to make sure they haven't cheated.

[@CasualTS]

1:22 This is not a creative writing assignment where you get to add your own ideas to the prompt or a detective mystery where you're trying find the missing clues. This is a math problem and you work with the premise given to you. I solved it by setting up an algebraic equation or as you described it "The Old Way"

[@erikkonstas]

No, Presh is saying the issue is like being asked to find the numeric value of x + 1, without being given any info about x, key words being *the* and *numeric* .

[@theomegajuice8660]

Incorrect. The premise given to you requires an additional unstated assumption that the 30 pages read on Monday were the FIRST pages read. It's a very reasonable and natural assumption to make (especially for a 5th grader who probably won't have had their basic assumption that "questions I am given will contain all the information needed to get an answer" challenged yet) but for the sake of completeness and pure logic this point is worth making on a channel like this.

[@gavindeane3670]

Exactly. These sort of things always attract a bunch of commenters who are really impressed with their own ability to apply maximal pedantry, despite having no ability whatsoever to know when that is and isn't appropriate.

[@gavindeane3670]

​@@theomegajuice8660Completeness??? If Presh's goal was completeness, he failed.

[@ollyrukes]

Of course, which is what the video shows, but the language in the question should be more precise and state “read the first 30 pages on Monday” so it’s clearer that’s when he started

[@gregjhill]

Thank you for solving it the old way.

[@onradioactivewaves]

I must have missed the abacus

[@Qermaq]

I read a bunch of books in this way until it came out right. Took several weeks, but I trust my results.

[@davidkaplan2745]

"No school like the old school".

[@jefffixesit60]

This is the kind of problem my 69yo autistic brain can solve almost instantly. I don’t know why that is, but it works for me. I had the answer to this problem before you finished reading the question. I’m glad you’re good at explaining math problems, it saves me from trying and failing to explain it to my friends and family! 😎❤️

[@Xebtria]

so he read 1/8 on Tuesday and 1/4 was left for him to read on Wednesday so Tuesday + Wednesday combined is 1/4 + 1/8 = 2/8 + 1/8 = 3/8. so the rest (what he read on Monday) is the rest of the full thing, meaning 8/8 - 3/8 = 5/8 5/8 = 30, so 1/8 = 30/5 = 6. so the full book is 8/8 = 1/8 * 8 = 6 * 8 = 48 pages.

[@taigenraine]

Stumped me for a few seconds until I re-read it and saw the word 'remaining'. Then it was easy. Assuming, of course, he didn't read any pages before Monday.

[@ibdense]

I was so lucky when I first started learning arithmetic back in the early 50s because I felt like this was a class where I got to play puzzles. It was fun. It was cool to be able to figure out these things. I never once had this fear and dread of mathematics. And I never once fell into that. When are we gonna need this after school mentality because I found myself using it in thewoodshop, and the projects I did as a graphic designer, and even sometimes in music. It was fun!

[@benardolivier6624]

You forgot to divide by the age of the captain...

[@Qermaq]

But who is the bus driver?

[@greatsville]

I'm 53, and some days I am smarter than others. Today, they're 5th graders.

[@kitchencone]

At 2:28 on, you could improve the graphics, by colouring the segments in the order they were read. Don't colour the first 1/8 segment green, colour the 5th one! It's still 1/8th, but it's in the right time position. Similarly, don't colour the first 1/4 segment green, colour the last one. It's the last 1/4 of the book that was read on Wednesday. _ _ _ _ _ _ _ _

[@TonboIV]

Because of the way the problem is presented, with "Klein" reading a certain amount per day, my mind immediately latched onto the _rate_ of reading and I tried figure that out, which was completely pointless and impossible. After a few seconds, I realized that the reading rate and the days he read on weren't even relevant and solved the problem easily, but I can imagine someone being lead down the wrong path and getting very confused. It's kind of a weird problem and strangely presented in my opinion. It feels like an overcomplicated mess for such a simple idea, which maybe leads one to dismissing the obvious and simple answer because it seems _too_ simple to be worth asking about in such a complicated way.

[@ryanburnham1932]

(30/x)+(1/8)+(1/4)=1 [Multiply by 8x] 240+x+2x=8x [Subtract 3x] 240=5x [Divide by 5] x=48 Figured 30 over the total pages plus the two fractional portions of the book had to equal 1 book.

[@blacksquirrel4008]

I am so happy I was finally able to figure out one of your problems during the pause.

[@lucienskinner-savallisch5399]

Since 30+1/8=3/4 I first swapped to decimals and used .75-.125=.625 to find 30/.625 gives you 48

[@dinisinacio3171]

Me being 10th grade and having solved it mentally the "old" way questioning if kids actually use rectangles to solve that now:

[@gavindeane3670]

I think the rectangles are just to illustrate the process. I solved it the first way but I didn't actually sit down and draw rectangles.

[@Chris-hf2sl]

The "old" way is usually called algebra. Don't they teach it in schools any more for some reason?

[@gavindeane3670]

​@@Chris-hf2sl10 year olds aren't learning the sort of algebra that he showed in the second solution in the video.

[@euromicelli5970]

I hate to be the old fogey, but… While visual intuition is useful on its own right, algebra is the master tool that opens the world. Kids don’t need to learn how to get-by on a grade school test with toy problems; they need to learn how to harness algebra for future complex problem solving in school and life. That’s how you train people to become engineers and scientists. And if you are not going to need algebra in your adult life these approaches are just as useless to you as algebra would be anyway.

[@Chris-hf2sl]

@@gavindeane3670 Well, that may be the case, but I don't think that the first method with the green boxes was any simpler.

[@sparkymlarky]

I worked it out in my head in 30 seconds

[@mrowlsss]

No, you didn't lol

[@vapyd3999]

@@mrowlsss don't see why not, it took me a lot less than that, mental arithmetic like this comes easy.

[@sparkymlarky]

@@mrowlsss It's pretty simple

[@angleth]

what are you gaining by asserting this lol is it public recognition?? I'm unsure but curious

[@obliviouz]

​@@mrowlsssIt's not hard, 1x - 1/8x - 1/4x = 5/8x, which was 30 pages. x = 48.

[@trinoxgamer]

As an Asian, i can confirm this is too easy for 5th grade

[@jamesgoudreau1940]

There has to be a level of trust between the people making the test and those taking the test. While being unsolvable if you assume the test maker was purposely leaving out key details, this is bad business. This is why I do not like trickery of any kind on a test unless, they tell the students ahead of time they will be purposely ask misleading questions. The rest of the world outside of school will provide plenty enough opportunities to learn of the dishonesty of others.

[@gavindeane3670]

Exactly. Amongst people who know *how* to apply maximal pedantry, not all of them know *when* to apply it.

[@matthewryan9323]

@@gavindeane3670 Something something something, Knowledge is the ability to be pedantic, Wisdom is understanding *when* to be pedantic?

[@SJrad]

Edit: I’m just gonna use a philosophical razor and say he started reading the book on monday, as there used to be no other information provided that would state otherwise. the creator of the problem could have assumed that it was clear that he started Monday without explicitly stating it. First find the fraction of the book the first 30 pages were. I will use p and b as units for pages and books respectively. 30p + 1/8b + 1/4b = 1b 30p + 3/8b = 1 b 30p = 5/8b so 30 pages is 5/8ths of a book. to find out how many pages is 1 whole book, multiply each side by 8/5ths to get 48p = 1 book. Checking the math, 1/8 of the book would be 6 pages, and 1/4 of the book would be 12 pages. 30+6+12 = 48

[@edithcunningham5713]

I feel lucky to have gone to elementary school many years ago in the UK when we had mental arithmetic regularly; and this would have been called sums, not the fancy maths of high school which we started at 11 years old. Such a superior education to today's in many ways.

[@shivanggupta8612]

Since 1/4th book is read on Wednesday So remaining 3/4 th book read on monday + Tuesday 3/4 of x = 30 + 1/8 of x x=48

[@dperreno]

Did it the "old way" in my head in 5 seconds. Thanks for the mini-challenge.

[@IsraelGersch]

0:18 I think 48 after thinking for a bit

[@davidbrown8763]

Thanks for the challenge. I nailed it in less than a minute using the second method, which is way faster than the first.

[@nonameform]

I did it the old way. I find it amusing that one of the first answers is always “it’s unsolvable” and an assumption that something is left out. ‘I’m not wrong, it’s the problem that sucks.’

[@antitheta777]

Despite having never learned the "new" way, that is basicly what my brain defaulted to when i did it in my head.

[@frofa2954]

same, and easily got the answer in less than half a minute.

[@gavindeane3670]

Me too. It's a quick bit of mental arithmetic. Reaching for an algebraic equation and manipulating it to a solution seems like massive overkill.

[@DandoPorsaco-ho1zs]

It took me about 10 seconds without a calculator. Truly challenging this problem.

[@aleksandersaski5387]

No wonder people have problems with this question. Who's ever seen a book that thin?!

[@matthewryan9323]

I know you're joking, but plenty of books for elementary school aged children (especially early grades when they're in the "starting to read for real" stage) would be that thin.

[@jesenjin8467]

This one was an easier to solve. Did variation of equation, but by multiply everything with 8 beforehand, so the numbers wouls be whole instead of 3/8 fraction.

[@honor9lite1337]

Easy 😒

[@bhgtree]

The possible _What If's_ have to be ignored, if the exam question doesn't give all relevant info then it can't be done properly (like about what day starting).

[@Qermaq]

For a 5th grade assignment, I agree. But if you got this question in a job interview they are probably looking for why it cannot be solved.

[@johnlarson505]

This is a good example of what people don't understand about common core. There is more than one way to think about how math can math.

[@studogable]

To echo the sentiments of others here before finishing the video: the combined reading of Wednesday and Friday is 3/8. Ergo, Monday's reading of 30pp must equal 5/8 of the book, making 1/8 of the book equal to 6 pp. 6*8=48. QED.

[@TheJaguar1983]

This demonstrates how phrasing can affect maths problems stated in a textual format. I agree that, if you take it as stated, where it doesn't *explicitly* state that Klein started the book on the Monday that he read the 30 pages, it is unsolvable. If you assume that it's not meant to be a trick question and that we have all of the information we need and it's implied that Klein did indeed start on Monday, it's just a matter of choosing the right method to plug the numbers into. There will of course be those who will still try to "outsmart" the question, whether because they legitimately feel that it should be interpreted in the unsolvable way due to the lack of explicit details, they enjoy exploring different interpretations of these sort of things and exploring more deeply, or just have a weird need to "prove" how smart they are to randoms on the internet.

[@gavindeane3670]

It's usually the last one.

[@frofa2954]

You must NEVER assume that it isn't a trick question, because usually they are. Not in this case, I admit. But these questions usually do not only give the needed information (which you would have in a non-textual math problem, in this case: solve 5/8x=30 for x), but a plethora of misleading "clues" to derail the normal student. This is done to trick and outsmart those who know the maths but may lose time to eliminate all the junk information. I find this ethically reprehensible, but that's how maths education works in many places.

[@gavindeane3670]

Don't be daft. It's a homework question for 10 year olds. It would be completely irrational to assume it's a trick question.

[@danielholowitski3855]

When i saw it was a 6 minute video i had to see the crazy alternate long way solution, but it never came

[@hadassahsoddsandends]

Oh did I do it the hard way! I multiplied all the fractions by 8 to eliminate them, then divided by five to single out the "x". Still came up with 48, but when I watched you with the boxes, I felt sooooooo silly!

[@gameknowledgeandit8934]

i just used the raito proportion mehtod 1/8 on tues day 1/4 on wendesday soo .125+.25= .375 1-.375= .625 soo 62.5 of the book = 30pg 100% of book= 100*30/62.5= 48pgs

[@ExplodingConsole]

It's been a long time since I've been in school so I haven't done stuff like this in a long time. Still, from the comments, I knew I was on the right track when I figured out 3/8 for Tuesday+Wednesday, so 30 pages is 5/8 of the book. I admit I stumbled next, but I'd like to think that's more from not doing this sort of thing in a long time then anything. Once I read the comments and got my brain to co-operate, just divide 30 by 5/8 to get the number of pages in the book.

[@nowknow]

My thought process: Let x = the total pages of the book. x(1/8)+x(1/4)+30=x x/8+x/4+30=x x/8+2x/8+240/8=x x+2x+240=8x 3x+240=8x 240=5x 48=x There are 48 total pages.

[@ColinRichardson]

It taken longer to read the question than to workout the answer.

[@Dragondog-Gaming]

Solving the problem in my head in seconds, I used the first method without the boxes. If I had written it down, I would have used the second method.

[@mittfh]

The 1/4 and 1/8 immediately stood out to me, so my first step was Tue = 1/8 and Wed = 2/8. Add the two together for 3/8, so Monday must be 5/8. Monday was 30 pages, so (30/5)*8 to get the total number of pages = 48.

[@cpsof]

If Klein had read a pages before Monday, then the equation would be: a + 30 + 1/8 * x + 1/4 * x = x, which gives: x = 8/5 * a + 48 So if a=0 (as assumed in the solution), the book would have 48 pages. If a=20, for example, then x=80. Saying that problem is unsolvable if the value of some constant is unknown, doesn't sound very mathematical.

[@ml198]

The most confusing part about this problem was “who names their child Klein?!”

[@traviscecil3903]

His father...Calvin.

[@lidarman2]

I don't get the ideas behind common core but maybe I am stuck in my "old" ways. I just hope all these young people who are learning common core grow up to be able to have the flexible reasoning to solve all the engineering and science problems they will face.

[@ValosiTiamata]

Common core is basically trying to teach math on an abacus (highly effective) without giving the child an abacus. It also relies heavily upon the exact grammar of a problem without allowing for basic mathematical principles such as 5x3 = 3x5 (commutative property), so the child has to learn ADDITIONAL terminology to explain how they went from 5x3 to 3x5 as an additional step in the problem to avoid their solution being marked wrong. In other words, someone saw what China was doing and decided to copy it without investing in an abacus for every student, then decided to do their best to remove the math aspect (because "math is racist") and turn them into grammatical problems that you have to solve by making an illustration representing an abacus and explaining in detail each step of using that abacus. It's substituting art class and grammar class for math class and expecting better results as someone teaching just simple math.

[@briant7265]

My approach was sort of a hybrid. I didn't try to set up an equation, but I also didn't try to match up blocks. 1/8 + 1/4 = 3/8 So Klein read 30 pages on Monday, and the remaining 3/8 on Tuesday and Wednesday. So... 30 pages = 5/8 6 pages = 1/8 And 6 × 8 = 48 Just step by step deduction and hardly any "math".

[@gavindeane3670]

​@@briant7265That IS the matching up blocks method. It's just that you already know how to do it, so you don't need someone to draw diagrams to illustrate how the thought process works.

[@gavindeane3670]

​@@briant7265That's exactly the solution he illustrates with rectangles and blocks in the video. Obviously those of us who already know how to think of it like that do not need a bunch of diagrams to illustrate the thought process.

[@TurquoizeGoldscraper]

It's like they're lawyers during cross-examination trying to poke holes in a witness' testimony.

[@SASA_maxillo]

I knew how to solve it immediately but i forgot to assign the whole problem to x (number of pages), that what made me stuck 😭

[@N0AHOfficial]

I solved this in sub-45 seconds. Assuming that there was no progress before Monday, the answer is 48. Simply just solve 30 = 5/8p, with p being the pages in the book.

[@derkatwork33]

This is a damning indictment of the public education system.

[@Zhiroc]

You know, to be fair I learned it the "old way" too... but I'm pretty sure this was in Algebra I which was 9th grade. So if this is really 5th grade, that's actually fairly advanced for that age. I still think the old way is more general since algebra is pretty fundamental, but I think it works for 5th grade math.

[@Asher0208]

Finally a simple question! Although I missed the "adult" answer that it is not solvable.

[@matthewmartinez3550]

For me, the "old way" was introduced later. For my 5th grade level, we would have taken 1/4 to be 2/8, and used 30=5/8 as a basis for converting the others in a table. While we would have variables at the time, it wouldn't be until year 6 that we'd do complex equations like that, and probably year 7 or 8 when we'd bring it all together for solving problems this way.

[@user-ox4ii2bw6x]

30=5/8, multiply by rhs's inverse, book unit = 48 pgs. done in moments

[@MrPaulc222]

30 + 1/8 = 3/4 30 = 3/4 - 1/8 30 = 5/8 6 = 1/8 48 pages. Slow reader. Yes, I did it in my head much faster, but the above is one of a number of paths.

[@SaintLouis-fe6nx]

1/4 of book was read on Wednesday that means 30+1/8 = 75% of the remaining book. 1/8 is 12.5% and since the total is 75% it implies: 75%-12.5% 62.5% Which means 30 pages are 62.5% of the total pages. So we can find total like this: 62.5%(x) = 30

[@rfactor1502]

I had this in a slightly different way. I basically saw a 1/4 and 1/8, saw that that was 3/8 because quarters and eights are fairly intuitive common denominators, and just solved for what would make 5/8x=30. Which is basically the old way with mental shortcuts that could resemble common core if put on paper.

[@gavindeane3670]

It's the new way without actually drawing the diagrams.

[@agent1gamez]

i did this in a slightly complicated way, by taking the no. of pages as x and then doing this: 30 + x/8 + x/4 = x 30 + 3x/8 = x (240 + 3x)/8 = x 240 + 3x = 8x 240 = 8x-3x 240 = 5x 240/5 = x 48 = x

[@chili015]

Did it in my head while sitting on a toilet. I pretty much did 30 + 1/8 = 3/4 (or 6/8)... 30 = 5/8 of total pages. 30 x 8 ÷ 5 = 48

[@ukdavepianoman]

I really find the "old way" much easier, but I guess this is not true for everyone. In my head I thought 30 + 1/8 P + 1/4 P = P, so 30 = 5/8P so P = 48. Although this problem is very simple, a good habit is to check answer...so 30 + 6 + 12 does indeed = 48.

[@JimmyMatis-h9y]

Its easy to assume it's 240 pages (30÷¼) but assumptions being what they are....😋 I say this is a perfect example of taking a few seconds to write out, as an equation, what the text is saying makes the problem very straight forward to (correctly) solve. 😊

[@geoffwhite3664]

OH, please! 8 seconds, give or take, it took me. In like 1.5 secs, I had 30 is 5/8 of the book. Divided 30 by 5, multiplied by 8 to get 48. Then I did it again in the other 4 secs to check my answer.

[@WatchesAhoy]

The Answer: 30.375

[@MichaelPaoli]

Easy peasy do it in your head - that's what I did: read 30 pages, then 1/8 of book, then 1/4 of book, that completed reading the entire book, so 30 pages + 1/8 + 1/4 = 1 (book), 30 pages + 1/8 + 2/8 = 30 pages + 3/8 (of book) = book, 30 pages = book - 3/8 book = 5/8 book, book * 5/8 = 30 pages book * 5/8 * 8/5 = 30 pages * 8/5 book = 240 pages / 5 = 48 pages

[@CatInABaseballCap]

It takes a minute to solve lol

[@beauthestdane]

More like about 10 seconds.

[@शाशांक]

​@@beauthestdanemore like 1/1000th of a sec

[@Nirakolov]

I did it wrong because I misunderstood the question, but still got the right answer; I took the second part of the question as tho there was 1/4 of the book remaining, therefor the sum of the first clauses must be equal to 3/4. 30+1/8x=3/4x (or 6/8x), subtract 1/8x from both sides to get 30=5/8x

[@PatGilliland]

or 30+1/8x=.75x 30=.75x - 1/8x 30=.75x-.125x 30=.625x x=30/.625 x=48

[@Rev03FFL]

Similar to the old way, I just converted Monday's reading to a fraction: 30/x. Then added the other two fractions to it and set the sum equal to 1 for the whole book. Solve for x.

[@deelkar]

I went with the equation x-30-x/8-x/4=0 because on Wednesday there are 0 pages left, and we start with x pages. This quickly resolves to the same path as the second solve. The question as stated needs two assumptions: a) the reading starts on Monday, and b) no pages have to be re-read.

[@koma7037]

If we assume, that there is an amount of y pages read before Monday, the equation becomes: y + 30 + 1/8x + 1/4x = x which is equal to 5/8x = y + 30, thus x = 1.6y + 48 so the book has 48 pages, when reading started on monday, else it has 48 + (1.6 * pages read through sunday) and that´s the answer🙂

[@annbate2590]

Geez you worked that so hard! 🤣😂

[@MrHealthWellness]

I can’t believe my 50 year old brain thought to setup an equation for x and solve it to get the right answer.

[@paulstudier5706]

My 70 year old brain did the same thing. Why is new math more complicated?

[@kanata_harumi]

This is quite intuitive... i guess people really hate math.

[@Kapcerballs]

This is one of those that makes me wonder how these people passed school. I'm one of the worst exampled of a student and I did this instantly in my head, it's like 3rd or 4th grade math.

[@JDrapic]

Before watching solution, the problem can be broken down into x=30+1/8x+1/4x -> x=30+x(1/8+2/8) -> x=30+3/8x -> 8x=240+3x -> 5x=240 -> x=48

[@TnegaLibram]

I did it a dumber version of the 'old' way: x = 30 + 1/8x + 1/4x multiply both sides by 8: 8x = 240 +x +2x Remove the unknown from one side: 5x = 240 divide by 5: x = 48

[@eugenel4394]

I simply created a formula of x - 1/8x - 1/4x = 30. From there, calculate for X which is total book length, which is 48.

[@djsyntic]

Okay paused at the start to try solve this one. Didn't feel like getting out anything to take notes on so did everything in my head. Only after did I come over here to type out my logic and answer. BTW the answer I reached was 48. So my thought is that if this problem contains all the information you need (for instance the kid didn't read some pages on a day not mentioned), then our our answer is 30 pages plus + 1/8th the book + 1/4th the book = 100% of the book. This would mean that 30 pages plus + 3/8th the book is 100% of the book meaning that 30 pages is 5/8th the book. 30 divided by 5 = 6 and 6 * 8 is 48. If I had to guess the reason adults are getting confused about this problem is that 48 pages for a book seem like a small number of pages while the number of pages the kid is reading each day is so much different from each other (30 pages, 6 pages, and 12 pages). This honestly reminds me of all those "A car is traveling from point A to point B and here is some made up details, now give us a specific piece of information that you'll need to solve" and I would always second guess my answer because the answer simply didn't make sense based on how I understood the world. IE: The car traveled 100 miles at 7 miles per hour, or whatever and I'm like "Surely that's far too low of a number because cars travel faster than that" Anyway, time to unpause the video and see if I'm right (perhaps I'm totally wrong because I am an adult and this is apparently stumping us). But I'm also curious if MYD goes into why adults are getting confused by this.

[@djsyntic]

And just finished watching the video. Glad to see we got the same answer, but a bit disappointed that MYD didn't go into thought about why people were getting it wrong. Again, I personally just link it to that an adult does not imagine a book with 48 pages as being a realistic answer and so assumes they have done something wrong. I just did a Google search for a normal length for a YA book and see it's about 200 to 300. Then just to double-check, I searched for how big of a book you expect a fifth grader to be reading and it came up with 150 to 250. So even if we go on the low end of that with 150, 48 pages still isn't even 1/3 the size of book an adult might imagine a child reading. I tried finding a 48-page book to see if I could find a good example and what I found were notebooks. The very same kind of notebook you might get your 5th grader to do their homework in. So yeah, I can see parents getting confused with this answer for what seems like a correct answer if they are having their child read books like Harry Potter (320 pages), Alice in Wonderland (352 pages), Wizard of Oz (259 pages), the Hobbit (304 pages) or other such books. I have heard a common criticism of Common Core isn't even the way it teaches math, but the examples it uses being more geared towards unthinking consumers that follow orders from their bosses. IE: 48 pages is the "perfect" number of pages for a workbook or manual and all that's expected of a cog in the machine. Why would a cog in the machine ever need to be reading books that are six times as long as that or more?

[@PratibhaBhadoriya-k2s]

Thanks

[@captainpolar2343]

1:17 OBJECTION! No kid does anything on Sundays except sleep and play games

[@ClassicGamer2996]

What I did was : (1/8 * 3) * 100 | 100% - 37.5% | 30 / 62.5% | 0.48 * 100 = 48 total pages I use this method since all of my assignments are point based and not percentages, so I have to use a calculator to find it.

[@ImmacHn]

The issue with the first method is that you don't build abstract intuition by doing it this way, most of the time learning the algorithm first and then deconstructing it helps you learn it better. The black box method basically. Don't understand something? Think of it like a black box. Once you know how to use the black box, disassemble it, you will find smaller black boxes inside, and you will have an intuition on how the larger one works, repeat process until you understand the whole thing. The new method is kinda backwards.

[@e4uclassrooms725]

Such an easy one. Can be solved without pen and paper

[@ZPPrograms]

I originally thought that the question said that he read a quarter of what remained on Wednesday, and that’s a very different question 😅.

[@tyger4186]

48 after about 20 seconds, it’s just a system of equations with 1 unknown

[@alexreid-wh9gq]

The way I did it was to change some items into percentages. 30 + 12.5% = 75%. 30 -= 75% - 12.5% = 62.5%. Then 30 : 62.5 X : 100% Cross multiply So, X = 30 x 100 /62.5 = 48.

[@kmyc89]

I solved in like a 1 minute in head, but of course- a bit different. Monday and Tuesday gonna be 3/4 B. 30+ B/8 = 3B/4 30 = 5B/8 240=5B B=48