What are Surds, and why are they special?

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  • Опубликовано: 25 окт 2024

Комментарии • 231

  • @Nofxthepirate
    @Nofxthepirate 6 лет назад +531

    These videos consistently distract me from my actual math homework because none of my teachers tell me WHY math works. They just want me to do the problems. I always want to know HOW mathematicians came up with this stuff and why it works!

    • @billyleecw
      @billyleecw 5 лет назад +22

      Nofxthepirate Math is the subject of the physical. It allows us to understand the workings of this world. Calculus, invented by Isaac Newton (And Leibniz) was what aided him in the understanding of physical, such as his famous and often abused F = ma. A pretty complex equation in itself (isn’t it physics? Yes but math and physics are closely related. One cannot happen without the other), it allows us to understand how the world works and how things work to put it simply.
      Elementary math like these teaches us the fundamentals to understand the workings of the world. It may not make sense now when you don’t see the full picture, but it is essential. Enjoy!

    • @jordanmckchicken3865
      @jordanmckchicken3865 5 лет назад +2

      @@billyleecw calculus was not invented by Isaac Newton

    • @monoman4083
      @monoman4083 5 лет назад +1

      google it..

    • @ganeshchavan2038
      @ganeshchavan2038 5 лет назад

      Same with me

    • @brandonstudie2941
      @brandonstudie2941 5 лет назад

      @@billyleecwThankyou.

  • @fenfox
    @fenfox 3 года назад +98

    His teaching methods are very simple but the main thing is that it all comes from his heart instead of simply his desire to earn money unlike most teachers today. We need more teachers like you, sir. We LOVE YOU!

    • @danm3213
      @danm3213 2 года назад

      Unlike most teachers today?? How do you know the intentions of 'most' teachers. You sound like an underachiever looking for somebody else to blame.

    • @SamuelsBookReviews
      @SamuelsBookReviews 2 года назад +2

      @@danm3213 you sound like a teacher

    • @heyitselsa152
      @heyitselsa152 2 года назад +9

      Desire to earn money?? Buddy I promise you no one is going into teaching for the sole burning desire of earning a ton of money lmao

    • @kyh148
      @kyh148 Год назад +2

      How much do you think teachers earn...
      Not enough to do a hard and stressful job just to earn the money. What I do suspect though, is that some might do it out of a desire for a little bit of power over students.

    • @stargazer7644
      @stargazer7644 Год назад +1

      Are you nuts? Nobody is a teacher because of a desire to earn money. Teachers don't make anything.

  • @thane9
    @thane9 4 года назад +77

    I love that his elevator music example was the girl from ipanema.

  • @fenfox
    @fenfox 3 года назад +27

    I usually come across this guy's videos while studying for my exam so I watch the videos partly even if they aren't related to my study topic. This time, I was so excited to see one of his videos and my topic match so I watched the video. I can say that I had seriously entered flow and I was enjoying it so much that I could've gone on for hours without a sign of exhaustion. Eddie sir, I simply adore the way you teach and hats off to you☺️

  • @0xb15h4l
    @0xb15h4l Год назад +1

    You are a legend Eddie!

  • @michaelnoronha7386
    @michaelnoronha7386 4 года назад +16

    Great work Eddie, Australia's children and virtue youtube, all your students are blessed off the stress of maths. God bless you.

  • @mitchelldaniel7985
    @mitchelldaniel7985 2 года назад +1

    Love how you are not telling us to do this equation and to show us how to do it but actually describe it and let us know the why part of the question. This even as a year 10 student has cleared my head a bit.

  • @4dr_14n2
    @4dr_14n2 4 года назад +23

    0:52 " You get a weird f*cking number"

    • @creativity8235
      @creativity8235 4 года назад +2

      laughed my ass off at that part haha

    • @arnavsinghal5142
      @arnavsinghal5142 3 года назад +2

      yea....i was wondering like did i hear that right...???
      😂

    • @Tfame
      @Tfame 3 года назад +8

      funky*

    • @irezak
      @irezak 3 года назад +2

      The teacher I wish I had, for sure for sure 😂

    • @alvarezkentalfe521
      @alvarezkentalfe521 3 года назад +1

      How did I not notice thissssss

  • @gerarddonovan4145
    @gerarddonovan4145 2 года назад

    Ur a good teacher in fairness to you.. Greetings from Ireland

  • @borisdorofeev
    @borisdorofeev 3 года назад +1

    Wow! I knew they called "irrational numbers", but did't know why! Thank you Eddie!

  • @muhammedali8025
    @muhammedali8025 6 лет назад +50

    A question for Mr Woo, I'd like to hear his way of explaining : How do they know it is actually irrational and doesn't reoccur after like a billion decimal places. How do you proove it's irrationality?

    • @forkevbot
      @forkevbot 6 лет назад +16

      Look up on youtube "proving the square root of 2 is irrational" you can do it because you can prove that it can't be written as a fraction. Then you just assume the same for many other roots.

    • @lelesecchi6140
      @lelesecchi6140 4 года назад +3

      You write down sqrt(2)=p/q, you tell that there's a rational number p/q equal to sqrt(2) and this is the hypothesis. Then you proove it by absurd, the equivalence can't be resolved because of even and odd number rules. That's it

    • @chrisofnottingham
      @chrisofnottingham 4 года назад +6

      There are two parts to answering this; The first is that if a decimal does repeat, it can be fairly easily shown that it must be expressable as the ratio of two integers and vice versa. This is actually part of the school mathematics curriculum. The second part is showing that the square root of any integer that isn't a perfect square, can't be expressed as the ratio of two integers. The easiest way to see this by considering a possible lowest form ratio a/b and putting a and b in terms of their prime factors. For a/b to be in lowest form there are no common primes between a and b. Thus when a/b is squared there are still no common primes and the ratio can never cancel to an integer.

  • @head85
    @head85 4 года назад +29

    I'm 35 today, have a Bachelor's in Mechanical Engineering from quite a reputable university, and I just discovered why "irrational numbers" are named as such😞

    • @borisdorofeev
      @borisdorofeev 3 года назад +1

      Same thing mate. 35 y.o. Bachelor Medical Science.

    • @julianbell9161
      @julianbell9161 3 года назад

      It seems to be an Australian thing

    • @jurajojo2543
      @jurajojo2543 3 года назад +3

      @@julianbell9161 No, he means the fact that "irrational" numbers mean numbers that cannot be written in a ratio

  • @chumsky8754
    @chumsky8754 7 лет назад +108

    Why, I never heard something so ab"surd"! :-)

    • @prabhusatyam7718
      @prabhusatyam7718 6 лет назад +1

      I studied surds in class 10th ....lol

    • @dengthiep1322
      @dengthiep1322 5 лет назад

      Surd is there, that's how I was taught in high school, might be wondering where you came from

    • @Loosehead
      @Loosehead 5 лет назад

      Oh my sides, please stop. No, please stop.

  • @chrisbroome
    @chrisbroome 6 лет назад +244

    Might be a U.S. thing but I've never heard of the irrational numbers being called Surds.

  • @graceelizabeth8435
    @graceelizabeth8435 5 лет назад +17

    Im in the middle maths class at my school because I transferred here at the beginning of the year and we aren't learning surds. That privilege is reserved for the top class. So I'm here to prove a point to my teacher that Im actually serious about my education and the things I learn even if she isn't.

  • @musmodtos
    @musmodtos 2 года назад +1

    06:31 - " _What kind of music would this be?_ "
    Me: Vaporwave?

  • @nehemiahchoi
    @nehemiahchoi 4 года назад

    Thanks Eddie Woo. Your work inspires my teaching. You are saying facts that are thought provoking.

  • @homemadesauce6153
    @homemadesauce6153 3 года назад +1

    Bro, the first time I heard "that's a weird f*cking number. I died

  • @abhii3350
    @abhii3350 5 лет назад +9

    Hello sir, I just browsing in order to get some knowledge over surds cause I have an exam😁😁😁. Well now I can right the exam and you're really an awesome teacher I've ever seen in my life.. You're friendly and making the concept getting on to the mind...

  • @HS143SH
    @HS143SH 4 года назад +2

    Great too easy explained . Love. From india 🇮🇳

  • @beyondhistory3039
    @beyondhistory3039 4 года назад +1

    **This guy is the most charismatic man ever **🔥

  • @cimex7492
    @cimex7492 4 года назад

    way better teacher than ive ever had in my life

  • @scanurasiri1
    @scanurasiri1 4 года назад +2

    Greatest maths teacher

  • @apporvaarya
    @apporvaarya 6 лет назад +14

    Amazing..I never have imagine such a analogy..😄😄

  • @RJSRdg
    @RJSRdg 4 года назад +2

    Poor kid's now been watched turning up late for school by 81K people!

  • @Smokyjohnson1983
    @Smokyjohnson1983 4 года назад +7

    Oh boy now you’ve done it... “Bass Guitar plays the same 4 notes throughout the song...”
    *Enter Davie504 🤪

  • @Aristothink
    @Aristothink 7 месяцев назад

    Great video, as always....but remember that although all surds are irrational, not all irrational are surds. "pi" and "e" are irrational but not surds. To be a surd we have to be inside a root....

  • @destructiveodst1199
    @destructiveodst1199 Год назад

    About to go into honours in maths and these videos are still fun to watch

  • @samm6871
    @samm6871 6 лет назад +24

    7:07 lol :D u missed half of the best maths lesson ever

  • @praveenmaxy7200
    @praveenmaxy7200 5 лет назад

    I'm 30 now I heard surds when I was 12 or 13,. now I know what surds are.....Truly u r a genius sir...

  • @LyfSukz
    @LyfSukz 4 года назад +6

    I'm so amused that he said it's not "irrational numbers" like "you crazy man" immediately after comparing irrational numbers to a crazy jazz musician lol.

    • @elimgarak7090
      @elimgarak7090 3 года назад +1

      I just now realized that irrational has the word ratio in it. Maybe, all this time, irrational means non-ratio :0

    • @LyfSukz
      @LyfSukz 3 года назад +1

      @@elimgarak7090 absolutely. You can sort of think of a fraction as a ratio of two numbers, and an irrational number is one that cannot be expressed as a fraction.

  • @simpleman283
    @simpleman283 2 года назад +3

    I did not see this teacher reply to any comments, so I don't know is he reads them or not, but I would like to thank him for the way he interacts with his students to get them interested in the lesson. Good on you Sir.

  • @izzatafiq1558
    @izzatafiq1558 3 года назад

    the moment he said sax for saxophone, i looked around to make sure my mum didn't heard it😂

  • @kevinwoo8593
    @kevinwoo8593 6 лет назад +3

    Crazy immortal jazz musician? Nice!

  • @anjalisharma1895
    @anjalisharma1895 3 года назад

    Your videos become my way of procrastination ..

  • @ashlingsprouster6855
    @ashlingsprouster6855 4 года назад

    mr woo you absolute legend

  • @theroutetomathematics
    @theroutetomathematics 3 года назад

    The Best teacher👌

  • @realmarker
    @realmarker 3 года назад

    “how many of you play an instrument?”
    Me: *puts hand up*

  • @SabiqHaque
    @SabiqHaque 3 месяца назад

    Hey Mr. Woo, I've a question for you: Why do irrational numbers exist?

  • @danielhobbs5806
    @danielhobbs5806 4 года назад +2

    This is fantastic! Thankyou for this quality content. You are doing the world a real service. Cheers

  • @tototiti1454
    @tototiti1454 3 года назад +1

    What about continued fractions representation of square roots? It might be interesting to show them that as a parallel of your ratio examples. (Someone might have already asked about it in a previous comment, I have read some but not found one about it so far)

  • @Apoorvpandey
    @Apoorvpandey 6 лет назад +2

    Impressive explanation .... got it at once !

  • @M4rtingale
    @M4rtingale 5 лет назад +7

    Tall and tan and young and handsome
    , the boy from South Australia goes mathing

  • @ThePiGirl
    @ThePiGirl 6 лет назад +1

    Brilliant lesson!

  • @ethanfang7927
    @ethanfang7927 Год назад

    Thanks Eddie ( I have math yearly tomorrow and this is one of the topics) [I Also have science]

  • @WhatIsThisAllAbout
    @WhatIsThisAllAbout 5 лет назад +5

    6:37 i actually raised my hand

  • @Loosehead
    @Loosehead 5 лет назад +3

    The key take-away is that surds can never be an exact representation of a value. Writing sqrt(7) is as exact as you can get.

  • @Mark73
    @Mark73 2 года назад +1

    Is the dot over the repeating decimal a regional thing? Because I always learned that it's a straight horizontal line over the number.

    • @meepsterling
      @meepsterling 2 года назад

      I've been told that you can use both, and they both mean and do the same thing

  • @melmelmel_
    @melmelmel_ 4 года назад

    My teachers have literally no idea how to teach this year. I'm failing extension maths because of their inability to explain anything! My maths teacher literally writes the rules and an example on the board while we copy them down in silence. At least this will be helpful when my school shuts down due to corona! Now that I found theses videos, maybe I won't fail!! Thanks!

    • @TheRedAzuki
      @TheRedAzuki 4 года назад +1

      Check out Khan's Academy, he helped me back in the days

  • @bg6b7bft
    @bg6b7bft 3 года назад

    Watched video, but still had to google what a surd is.
    The missing info was that a surd is a _type_ of irrational number formed from the square root of a rational number. It's not just Austrailian for "irrational number".

  • @vinceperry769
    @vinceperry769 6 лет назад

    Numbers that "terminate" do in fact repeat the repeating sequence being a zero by itself.

    • @vincent-ls9lz
      @vincent-ls9lz 4 года назад

      good to know, but in mathematical notation that's just assumed. Same way how a blank '2' always means positive 2; we never write +2.

  • @Jeanstravels
    @Jeanstravels 5 лет назад

    Omg your Videos are so gerate thank you for filming that:)

  • @peterlawrence4087
    @peterlawrence4087 5 месяцев назад

    7:09 being the most replayed is funny lol

  • @SteveJones313
    @SteveJones313 2 года назад

    Not gonna lie, I had to rewind because I really misheard what you said at 0:53

  • @kiel5390
    @kiel5390 4 года назад

    that kid who couldn't find the class
    hahaha

  • @vivekd005
    @vivekd005 2 года назад

    7:06 That Kid must be thinking, only if I came early that day

  • @flamephlegm
    @flamephlegm 5 лет назад +1

    I think in the U.S. we would put a line over 0.3 and refer to it as "point three replicant" or something.

    • @papajulietromeo-650
      @papajulietromeo-650 5 лет назад +1

      Same in Germany. We also use the line notation, but call it "period".

    • @flamephlegm
      @flamephlegm 5 лет назад

      @@papajulietromeo-650 That's cool! Thank you for sharing!

    • @papajulietromeo-650
      @papajulietromeo-650 5 лет назад +1

      @@flamephlegm I've noticed several differences in his notation compared to what I learned in Germany, e.g. in other videos he puts arrowheads on both sides of a coordinate system axis. I learned that you should always only mark the positive end of the axis. It's interesting that mathematics, which is often considered to be the universal language of science and engineering, can be written in sometimes ambiguous ways. Dot-above-something could also mean "derive with regards to time", dx(t) / dt.

    • @flamephlegm
      @flamephlegm 5 лет назад +1

      @@papajulietromeo-650 the commas in numbers in Mexico still throws me off in a big way.

  • @rialtho_the_magnificent
    @rialtho_the_magnificent 7 лет назад +6

    Is that a typical Aussie accent? Surds, that is?

  • @epicuber1351
    @epicuber1351 2 года назад

    I watched this video with popcorn lol

  • @nekogod
    @nekogod 5 лет назад

    One thing, you said ''not like 'you're being irrational you crazy man''' aren't irrational numbers the exact reason why we use the word irrational in that context?

  • @samuelwillowcreek8764
    @samuelwillowcreek8764 4 года назад +1

    Wait did he sing "The Girl From Ipanema" as the "elevator" song?

  • @jackmandu
    @jackmandu 5 лет назад +1

    Was the elevator music he was humming, The Girl from Ipenema?

  • @BlueGiant69202
    @BlueGiant69202 3 года назад

    Could using the word 'square' rather than 'triangle' create some misconceptions similar to saying 'I saw the sunrise'?

  • @TenguSteel
    @TenguSteel 4 года назад

    Why not use the term transcendental number for when a square root does not result in an integer and always results in a transcendental number there are other transcendental numbers of course

  • @BekahBBlade
    @BekahBBlade 6 лет назад

    So they're... ABSURD!!! LOL

  • @yumenokira7595
    @yumenokira7595 4 года назад +2

    I wonder what would think the boy who came late to the class about his math teacher speaking about guitar when he came in

    • @RJSRdg
      @RJSRdg 3 года назад

      That kid coming in late is now on youTube for eternity!

  • @lokeshraghavendra1159
    @lokeshraghavendra1159 4 года назад

    I wish this guy was my math teacher

  • @ikeabuchi1
    @ikeabuchi1 4 года назад +2

    "Crazy man" =irrational
    "Crazy man" =Ab(surd)

  • @ozgacity
    @ozgacity 4 года назад

    Love your channel, but to be truly rounded, remember you can revert, but you can't revert back because back is already contained in the definition and to do so is a redundancy

  • @samuelmahatma9273
    @samuelmahatma9273 3 года назад

    Thank you

  • @RTD553
    @RTD553 2 года назад

    Not quite 'dot dot dot' after the calculator's final digit - the calculator has actually rounded to that last sig. fig.

  • @An_Iron_God69420
    @An_Iron_God69420 Год назад

    damn i didnt realize this was 8 years ago, or instead of the crazy immortal jazz musician analogy, he'd just call it ai.
    Times change huh.

  • @peterciurea7771
    @peterciurea7771 6 лет назад +6

    So are Surds short for ABsurd?

    • @RJSRdg
      @RJSRdg 3 года назад

      Only if it's the square root of AB...

  • @jameshumphreys9715
    @jameshumphreys9715 6 лет назад +1

    There is a way of doing square roots, that don't have perfect square roots, finding the nth tooth, which is like a long division way or the Babylonian method

  • @76koma
    @76koma 6 лет назад +1

    Different analogy for music :P spotify playlist. popsong is one song one, elevator music, is playlist on repeat on given order. Crazy jazz music is random playlist which also takes in spotify suggestions, it never goes to exactly same repeat...

  • @twp007
    @twp007 5 лет назад +3

    For the surd, the Music might be likened to the music played by a wind chime.

  • @zackmaradeen5902
    @zackmaradeen5902 4 года назад

    @Davie504 Eddie Woo is a bass player confirmed? Please make a video about this

  • @uncertainhopes8547
    @uncertainhopes8547 4 года назад

    Which camera you use ?

  • @ericsills6484
    @ericsills6484 4 года назад

    Wow, there is a difference here in America. We use a bar over the number to represent repeating.

  • @losedolla6590
    @losedolla6590 4 года назад

    3:40 in Germany we use a line over the three instead of a dot🤔

    • @flinthart
      @flinthart 4 года назад +2

      We use a line too (actually both), but we usually use it when there are 2 or more numbers repeating like 0.65656565656565....

  • @hareecionelson5875
    @hareecionelson5875 3 года назад

    5:12 Is he going to say Jazz? I haven't watched to the end yet...
    EDIT: There are no wrong notes in Jazz

  • @VKNATIONWATCH
    @VKNATIONWATCH 3 года назад

    Year 10 maths, J.T + Mitchell watched the video

  • @Roger-hu4tk
    @Roger-hu4tk 3 года назад

    What is this class? High school or college?

  • @Nick-ui9dr
    @Nick-ui9dr 5 лет назад

    Surds are absurds! No? ...Then why they sound like it? Peers must have thought something before naming them. :)

  • @nikhil_06_
    @nikhil_06_ 5 лет назад

    So is "pie" a surd as it can be written as 22÷7 but it's decimal places doesn't repeat in a certain pattern?

    • @0Coeus
      @0Coeus 5 лет назад +1

      Pi is irrational and can not be written as a fraction. 22÷7 is just an approximation :) (according to my calculator only accurate to the second decimal place, so not a very good approximation)

    • @carultch
      @carultch 4 года назад

      Surds involve square roots of integers in order to define this. Numbers like pi and e eare beyond this, in terms of how disconnected from ordinary numbers they are.
      Pi and e classify not only as irrational, but also as transcendental. Surds are part of a classification of irrational numbers called algebraic numbers. Transcendental numbers are numbers that are not algebraic, rational, or integers. Numbers that transcend algebra, as in go beyond algebra.
      Algebraic numbers are roots of polynomials with a finite number of terms. These are numbers that involve roots, whether square roots, cube roots, or even roots of higher orders. But the point is, there is a finite number of terms in identifying an algebraic number in terms of 4-function math and roots.
      It takes an infinite number of terms in the polynomial, for a transcendental number to be the root of the polynomial. It is common that these numbers are identified as an infinite series, that give a means of calculating them. That is, a pattern of numbers that when added up, will converge to this value.

  • @vinceperry769
    @vinceperry769 6 лет назад

    square roots of numbers that are not squares are all irrational as are all radicands that are not bases raised to radical indices.

  • @lucasfreire1090
    @lucasfreire1090 4 года назад

    At 0:53 I swear I heard him say "weird fucking number"

    • @roninnib6635
      @roninnib6635 3 года назад

      Funky

    • @lucasfreire1090
      @lucasfreire1090 3 года назад

      @@roninnib6635 i know, mate, that's why I left a comment, because It sounded like it

  • @OCV102
    @OCV102 5 дней назад

    technically surds can be written in a ratio eg 2*√7 / 2 ok I will excuse myself out haha

  • @goman9998
    @goman9998 3 года назад +1

    Sir we can write 5 as 5/1 and this is rational then why √2 /1 is not rational

    • @JDela10
      @JDela10 2 года назад

      5/1 is not the same thing as sqrt(5) though, the same as 2/1 is not the same as sqrt(2). Technically, 5/1 is sqrt(25), and 2/1 is sqrt(4).. kinda.. also have to remember our negatives can be squared.
      Sqrt(2) / 1 is not the same as 2/1.

  • @callumnorthcott1006
    @callumnorthcott1006 4 года назад

    this is good

  • @WhitePegasus326
    @WhitePegasus326 4 года назад

    7:09 that chad tho

  • @ganeshchavan2038
    @ganeshchavan2038 5 лет назад

    Can anyone tell me, this lecture is of what standard ( grade) ??

  • @barryhughes9764
    @barryhughes9764 6 лет назад +1

    So is the square root of a rational number irrational? Confused !

    • @Lashb1ade
      @Lashb1ade 6 лет назад +2

      Sometimes it is irrational, sometimes it isn't.
      First look at integers (whole numbers): If you take the square root of a square number (1, 4, 9, 16,...), you get a rational number out. If you take the square root of a non-square number (2, 3, 5, 6,...), you get an irrational number.
      Now consider fractions: If you take the square root of a "square fraction", e.g. "1/4" or "4/9" you will get a rational number (for our examples the answers will be "1/2" and "2/3"). If you take the square root of a fraction with non-square numbers in it, e.g. "1/3" or "3/4," then you will get an irrational.

  • @shashank_kishore_
    @shashank_kishore_ 4 месяца назад

    ❤❤❤❤❤❤❤❤❤

  • @sareenasaadie3455
    @sareenasaadie3455 Год назад

    can he be my math teacher 😭😭

  • @plame3843
    @plame3843 4 года назад

    0.50-0.55, he says 'fucking'? someone please confirm!

  • @Nick-ui9dr
    @Nick-ui9dr 5 лет назад

    But why it goes nonrecurring? What makes them go changing patterns? ...U can also answer by why in some got reoccurring pattern... that will explain it too I suppose. :)

    • @carultch
      @carultch 4 года назад

      You get the recurring pattern for rational numbers, because it is a ratio of integers. Eventually, every denominator that doesn't form an ending decimal, will be a factor of a number like 9, 99, 999, 9999, etc. In the case of 1/3 and 1/9, we can express them as fractions out of 9. In the case of 1/11, we can express it as fractions of 99. Less obvious, in the case of 7ths, we can express it as fractions of the number 999,999. The number of 9's that form this grand multiple of the denominator in question, tells us how many digits get to repeat. 1/3 equals three ninths, thus repeats the digit 3. 1/11 = nine ninety-ninths, thus repeats the digits "09". 1/7 = 142857 / 999999, thus repeats the digits "142857".
      For this reason, only rational numbers can have repeating patterns of digits in their decimal form. If there is a repeating pattern of digits, there exists a number made up of 9's from which it is a factor. If it is irrational, by definition, it cannot be a fraction of anything, so its digits must not form repeating patterns.

  • @sujeetjangra1161
    @sujeetjangra1161 2 года назад

    Okkk... But why are they special?

  • @GamerSaga
    @GamerSaga 4 года назад

    parts of these video are rational, though also irrational but mostly just ab' surd!

  • @timmy18135
    @timmy18135 4 года назад

    It sounds like he is teaching teens