Introduction to rational and irrational numbers | Algebra I | Khan Academy

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  • Опубліковано 27 гру 2024

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  • @rin-sd2ql
    @rin-sd2ql 6 років тому +1690

    Thx you teach better than my real math teacher

  • @xedd7627
    @xedd7627 5 років тому +266

    I wish you were my teacher ;-;

    • @robbi3tk
      @robbi3tk 4 роки тому +22

      If you're watching this video and focusing on the content, he is your teacher ;)

  • @ghufranahmed3062
    @ghufranahmed3062 5 років тому +446

    My teachers at school made me learn for years but still i failed in this topic
    Today morning I watched this
    Wow i passed!
    Love you Khan Academy
    Youuuuu so great!
    I don't have words, I am so happy
    Thanks!

    • @artsandcrafts6863
      @artsandcrafts6863 4 роки тому +3

      Ghufran Ahmed hey are you wahaj and Ghufran cuz I think your my cousins I’m watching this in 6th grade XD

    • @zethumpanza9197
      @zethumpanza9197 3 роки тому +4

      Congratulations🤩😘😜

    • @AlexTheNiceGuy
      @AlexTheNiceGuy 2 роки тому

      @@artsandcrafts6863 i wasnt able to find it there so i searched on yt and found the right video

    • @ryannjones6456
      @ryannjones6456 2 роки тому

      yes

    • @walabalawalaaussie2832
      @walabalawalaaussie2832 Рік тому

      khan academy skill

  • @rubyyxlc3936
    @rubyyxlc3936 6 років тому +61

    3:41 Irrational numbers, my timestamp for future reference

  • @teendailymotivation9817
    @teendailymotivation9817 5 років тому +480

    Khan: " Today were gonna learn about rational numbers... rational numbersss.."
    Student: "Okay I get it rational num- "
    Khan: " Rational numberss... rationallll numbers..."

  • @ETS_Coltix
    @ETS_Coltix 8 місяців тому +2

    10yrs later and ur still teaching me new things. Thank you for being in my life as an ACCUAL teacher

  • @newt122
    @newt122 8 років тому +442

    Iiiiiiiiiiirratinal Numbers.... Iiiiiiirtatinal Numbers..... Iiiiirrational Numbers......
    X)
    XD
    I love how he says it! XD lol.

  • @Y15-t4h
    @Y15-t4h 6 років тому +434

    Who is just looking down in the comments while there watching the video 😝 maybe it is just me okay 👌🏻

  • @imbaka4083
    @imbaka4083 3 роки тому +8

    I feel like teachers in school most of the teachers really are confusing and don't explain well youtube has helped me a LOT in math and I really thank khan academy for helping me :)

  • @rasbanikaur2122
    @rasbanikaur2122 8 місяців тому +2

    Rational numbers are ratios of integers, including decimals with patterns. Irrational numbers, like pi and the square root of2, never terminate or repeat. There is always an irrational number between any two rational numbers, and the sum or product of an irrational and rational number is also irrational.
    [00:00] Rational numbers are ratios of integers, including non-integers like 3.75, which can be represented as 375/100 or 15/4.
    - Integers are rational numbers
    - Non-integer rational numbers can be represented as the ratio of two integers
    - Examples of non-integer rational numbers include 3.75, which can be represented as 375/100, 750/200, or 15/4
    [01:56] Rational numbers can be represented as the ratio of two integers, but some famous numbers in mathematics are not rational.
    - Rational numbers can be expressed as a fraction of two integers
    - Repeating decimals can also be represented as the ratio of two integers
    - Some famous numbers in mathematics, such as pi, are not rational
    [03:47] Irrational numbers are exotic but not uncommon, with an infinite number between any two rational numbers.
    - There is always at least one irrational number between any two rational numbers
    - Taking the square root of any non-perfect square or adding an irrational and a rational number results in an irrational number

  • @ao0zero
    @ao0zero 7 років тому +83

    thanks i have a test tmrw XD

    • @zerologyy5577
      @zerologyy5577 5 років тому +1

      whatcha get on that test bro

    • @Sync-Edits
      @Sync-Edits 5 років тому +3

      The comment was posted 2 years ago

    • @v43h
      @v43h 4 роки тому

      Me to🤣

    • @zh96131
      @zh96131 4 роки тому

      Same here altho u had the test 2 years ago but okay

  • @druhanperera
    @druhanperera 4 роки тому +24

    The one time I pay attention in class

  • @DuckSquad4
    @DuckSquad4 9 років тому +69

    I'm glad the "PAUSE" button is here so people can "pause" the video whenever they like and have a look at what the person in the video is trying to teach so they can stop and have a think about it!

  • @mcmuffin446
    @mcmuffin446 Рік тому +9

    if anyone is still confused,here is the definition in simple terms
    *Rational Numbers* : All the numbers in the form of p/q,aka fraction,where "q", aka denominator,is not a zero are called "rational number".It's denoted with the capital letter "Q"
    *Example* : {2/6,4/8,9/4,....}
    *Irrational number* :literally any number with the square root sign "√'"
    *example* : {√'3,√'8,√'100,√'pi.....}

    • @fearnot90sm
      @fearnot90sm Рік тому

      Except for perfect squares. square root of 100 is equal to 10 which is a rational number

  • @royaleplayzyt9690
    @royaleplayzyt9690 4 роки тому +9

    Is it just me or is Sal's voice soooo calm!

  • @suhebkhan8139
    @suhebkhan8139 6 років тому +33

    FANTASTIC WAY OF TEACHING SIR... AWESOME

    • @MaxxAndKfox
      @MaxxAndKfox 2 роки тому +1

      is your caps lock stuck on?

    • @foxyolk
      @foxyolk Рік тому

      ​@@MaxxAndKfoxfr

  • @monazcoolirani
    @monazcoolirani 10 років тому +192

    i think the khan academy dudes voice is close to Morgan freeman's

  • @-DiveForIve-
    @-DiveForIve- 5 місяців тому +1

    00:05 Definition of rational numbers
    01:03 Understanding rational and irrational numbers
    02:00 Rational and irrational numbers can be represented as the ratio of two integers or repeating decimals.
    02:36 Representation of repeating decimals as ratios of integers
    03:18 Rational numbers include integers, finite non-repeating decimals, and repeating decimals.
    04:12 Irrational numbers never terminate and never repeat.
    04:46 There is always an irrational number between any two rational numbers.
    05:25 Understanding the properties of irrational and rational numbers

  • @tableswithoutchairs1168
    @tableswithoutchairs1168 4 роки тому +11

    i had 2 choices, watch a video my teacher sent me that explains to me the exact same thing, but takes 16 minutes, or watch this. and of coarse i chose this! this is really helpful

  • @rakeshthakur8384
    @rakeshthakur8384 4 роки тому

    You are god gifted men. Because no teacher can explain this chapter in 5min.

  • @lynxth3wuf969
    @lynxth3wuf969 5 років тому +14

    thank you so much! this helped a ton. your voice is so soothing to listen to and you're simple and straight to the point. I like it! 🌻

  • @mrxarch
    @mrxarch 3 роки тому +2

    our teacher was teaching us for a month just for this and no 1 learned it
    but now i fully understanded it in 5 minutes
    i wish i could pay some thing for u

  • @Mariaツ-y3d
    @Mariaツ-y3d Рік тому +6

    My math teacher took 3 days to explain everything and this man takes only 5 MINUTES TO EXPLAIN.

    • @rupeshranjan8769
      @rupeshranjan8769 Рік тому

      Which class??
      Me 9th

    • @glemmstengal
      @glemmstengal Рік тому +1

      There are as many as 30 different learners in a classroom and not all of them learn as fast as you or as easily as you. Get some perspective.

    • @Mariaツ-y3d
      @Mariaツ-y3d 11 місяців тому

      @@rupeshranjan8769 9th as well

  • @ethernity9
    @ethernity9 4 місяці тому

    I love that you basically answered this within 30 seconds of starting the video. It wasn't obvious to me until you emphasized the "ratio" part of rational numbers.

  • @miasims7575
    @miasims7575 6 років тому +59

    I still can’t really understand it, but I just needed to know how do you get a irrational number.. so thanks 🙃

  • @mattpeirce2635
    @mattpeirce2635 7 років тому +91

    😂I watched this 15 times in a row because my math regents are tomorrow

  • @bhoopalani7256
    @bhoopalani7256 4 роки тому +10

    I have a silly doubt.. what if 22/7 becomes something like 3.1415926535914159265359 (Just an example) Then pi has a repeating pattern of 14159265359. It should then be considered rational right?
    What I exactly ask is... do we have a number of digits after which we should not consider it as rational even if it repeats? I find it very hard to put into a question. But believe me, I have visited a LOT of videos on irrational numbers and only your video is satisfying. So I'm sure you understand me.

    • @aarnar8518
      @aarnar8518 Рік тому

      Ur question is confusing

    • @kings-Rex
      @kings-Rex Рік тому

      You make perfect sense. It's a grey area that probably needs clarification

    • @bhoopalani7256
      @bhoopalani7256 Рік тому

      Thanks. Probably should ask gen ai I believe. Hope chatgpt doesn't bluff this time

  • @yuzunoii8523
    @yuzunoii8523 2 роки тому +1

    few hours left until exam and im so glad i found this helpful vid :0 and also...gahdamn that voice tho. its majestic ^3^

  • @mr.trollge766
    @mr.trollge766 2 роки тому +8

    I like these types of videos, not because of the math, but because they way he writes perfectly with that writer

  • @brook.f
    @brook.f 6 років тому +32

    "And we call these numbers, Irrational, iiraationalll, irraaaatttiiiooonallll, iRaTiOnALlLLLLlllLLLLlLLLlL
    LlllllllL" 👏👏😂

  • @akssagir5411
    @akssagir5411 Рік тому +3

    I wish i had these time of foreign teacher in pakistan.

  • @EZ-kq9xj
    @EZ-kq9xj 3 роки тому +11

    POV: you have a test tomorrow and you ARE NOT READY

    • @ajtessman
      @ajtessman 3 роки тому +2

      Yes... What did you get?

    • @EZ-kq9xj
      @EZ-kq9xj 3 роки тому +4

      @@ajtessman a 67 😭

    • @ajtessman
      @ajtessman 3 роки тому +3

      @@EZ-kq9xj I got a 45 😭😭 then I did a retake and got 70

  • @gargeeprakash
    @gargeeprakash 3 роки тому +9

    Every students bias is KHAN ACEDEMY!!
    Thanks a ton.

  • @moizkhalid2714
    @moizkhalid2714 7 років тому +9

    good to revise basic concept
    👉💯✔👍✌

  • @AdamKrivoshein
    @AdamKrivoshein 10 років тому +27

    Thanks so much. Your videos are exceedingly helpful in a simple easy way.

  • @AnandhaKrishnanPT
    @AnandhaKrishnanPT 4 роки тому +3

    The Ratio between the Circumference and Diameter of any Circular objects like Small Ring to Big Moon always is π (Pi)...
    For example, Take a small Ring.
    Using thread measure it's Circumference (C)
    and Diameter (d).
    Now,
    C/d = one answer in Numbers....
    Next imagine you are measuring Moon Circumference (C) and it's Diameter length. The ratio is:
    C/d = gives the same answer in number what we got in the case of small Ring.
    Conclusion:.
    C/d = Same number every time...
    That same number is π....
    C/d = π .
    So the circumference of a Circle formula is C/d = π
    C = πd
    C = π (2r)
    C = 2πr units...
    Pi is the 16 th Letter of Greek Alphabet.... Almost maximum Maths Symbols we are using is Greek Language Letters....
    Difference Between Rational and Irrational Numbers:
    Rational Number:
    It has Non-Terminating and Repeating (Recurring) places of Decimals.
    Example: 10/3 = 3.33333333...
    22/7 = 3.142857 142857 142857.....
    Irrational Number:
    It has Non-Terminating and Non-Recurring places of Decimals.
    Example: √2 = 1.412135623
    π = 3.1415926535 8979323846 2643383279 5028841971 6939937510 5820974944 5923078164 0628620899 8628034825 3421170679 ...
    Hence Real Numbers = The Set t of Rational Numbers + The Set of Irrational Numbers...

  • @Intellectualcuriocity
    @Intellectualcuriocity 5 років тому +7

    I am 35 and learning this.. wish I had access to internet during school days

    • @arifafahmida4045
      @arifafahmida4045 4 роки тому +1

      Very bad.but why r u learning this useless thing?learn coding or languages or anything u like

    • @Intellectualcuriocity
      @Intellectualcuriocity 4 роки тому

      @@arifafahmida4045 learning coding or csc without basics in math...

    • @HUZIAFA.KHAN123
      @HUZIAFA.KHAN123 4 місяці тому

      ​@@Intellectualcuriocitybro your lucky you didnt had Internet its distraction bro at your time you had 4 distractions now we have 40 there's difference bro

  • @arynx1245
    @arynx1245 2 роки тому +1

    i love how he sounds excited even talking about math, it helped me understand this more somehow :)

  • @themecha1698
    @themecha1698 3 роки тому +15

    Thanks khan academy... today at school we were learning Zeno's paradox and I could not understand it. Now after watching this amazing video, I am happy to say that now I understand it

  • @Shougss-z2t
    @Shougss-z2t Рік тому

    How could this video be so beautiful? How could this teacher be so amazing?!!! I can't believe this video was 9 years ago..

  • @HungerSlice
    @HungerSlice 7 років тому +8

    Amazing explanation. I feel a little obfuscated how the majority of your viewers did not understand. There could not be a better explanation. Some ignorant people are asking peculiar and sarcastic questions like : What's a rational number? Didn't you freaking the video? Its a number that is either recurring or can be placed in a ratio/fraction format! Thank you so much for this video. I've been a little bewildered by this topic. I'm currently in grade of and definitely know that there are millions of topics to cover and a long journey stands before me!

    • @HungerSlice
      @HungerSlice 7 років тому +2

      Didn't you freaking watch** the video? I can't seem to find the edit button

    • @HungerSlice
      @HungerSlice 7 років тому +3

      Grade 9*
      It's*

  • @Incepter.
    @Incepter. 2 роки тому +5

    WOW MATH RATIONAL AND IRRATIONAL NUMBERS IS SO EASY I NEEDED THIS FOR MY SCHOOL CLASS THANKS KHAN ACADREMDY

  • @smithavijay332003
    @smithavijay332003 5 років тому +4

    Awesome it became so easy for me and helped mea a lot thanks a lot

  • @sirsparks7517
    @sirsparks7517 3 роки тому +2

    helpful info thanks

  • @that_one_septiplier_fan1881
    @that_one_septiplier_fan1881 8 років тому +209

    This seems like highschool.... Only a 7th grader... ;-;

    • @Dream-ql9hg
      @Dream-ql9hg 8 років тому +22

      Im a 6th grader ;~;

    • @dumeka-miller8191
      @dumeka-miller8191 8 років тому +3

      Me too

    • @mahiranasiraziz
      @mahiranasiraziz 8 років тому

      Manly Fairies me too😘😘

    • @amyshin1693
      @amyshin1693 8 років тому +7

      i wonder "why" its called "introduction" to rational and irrational numbers...

    • @4MY4KIDS
      @4MY4KIDS 8 років тому +1

      That_One_Septiplier_Fan Ima 6th grader... this is too hard for me!

  • @MukeshKumar-qz8xt
    @MukeshKumar-qz8xt 7 років тому +3

    Thank you very much sir for clear my concept on rational and irrational number

  • @Jess-cw1is
    @Jess-cw1is 6 років тому +10

    thanks I finally found a video that helps me:) hopefully I pass my test tomorrow:)thanks

  • @vinered4096
    @vinered4096 8 років тому +1

    You are so awesome, let the haters hate because they're nothing in life.

    • @SreenikethanI
      @SreenikethanI 7 років тому

      True...

    • @SreenikethanI
      @SreenikethanI 6 років тому

      *EnglishPremierLeague Central* kind-of yes
      Btw I am in 8th grade now

  • @bernardmcintyre1550
    @bernardmcintyre1550 7 років тому +6

    a very educational video I recommend it for teachers all over the world

  • @jaugerot6401
    @jaugerot6401 8 років тому +1

    This is a review I have to use for midterms tomorrow

  • @ashleyp8328
    @ashleyp8328 7 років тому +88

    Is anyone else 23, graduated from college, and only here reviewing because DAT Bootcamp told you to? .... Just me? Okay

  • @ayatbrown1913
    @ayatbrown1913 2 роки тому +2

    Bro u teach me better than my math Teacher

  • @maymamii
    @maymamii 5 років тому +4

    Super great video it helped me a lot! thanks bro.
    :)

  • @Count_Courage
    @Count_Courage Рік тому +1

    Im here because im refreshing my memory for college working from Pre Algebra to Calculus my father is a math teacher and gave me his books

  • @MooMooMath
    @MooMooMath 9 років тому +8

    Thanks for the clear explanation of rational and irrational numbers. Putting a label on different numbers can be confusing.
    I liked your video so muchI linked to your video in my video notes.

  • @Scholarszilla
    @Scholarszilla 4 роки тому +1

    By taking inspiration from your videos , Making videos in Hindi / Urdu.
    You are great.

  • @chur1k5
    @chur1k5 3 роки тому +2

    Khan Academy is fantastic, although it needs some upgrades on their website, Other things AMAZING! I have a good math teacher (Indian obviously) But he talks fast :/ So I searched this on UA-cam for my exam, I am confident with this, Thanks.

  • @imanahmad2780
    @imanahmad2780 4 роки тому

    I have been watching you for 4 years now and i am now getting the chance to subscribe

  • @jessicaspencer4908
    @jessicaspencer4908 10 років тому +9

    what app do you use for your videos and how much did it cost???

    • @jakedavis7950
      @jakedavis7950 6 років тому +5

      That's photoshop. I think its a modifier/add on or something that makes it to where you can draw on it like a chalk board.

  • @angxls7322
    @angxls7322 3 роки тому +1

    Thank god we found you we didn't understand this so me and my mom learned something before I failed

  • @Oriss81
    @Oriss81 4 роки тому +20

    When there’s a break during lecture I come here to actually understand it.

  • @comfortogunyemi9254
    @comfortogunyemi9254 2 роки тому +1

    Thanks I took a nap during class and am struggling on homework rn

  • @imadejaber126
    @imadejaber126 8 років тому +3

    its a good thing his explanation is very simple you make you understand queckly

  • @Arx7_34
    @Arx7_34 Місяць тому

    'preciate it🔥🔥I'll be back in 5 years to thank you again

  • @ayanakif7962
    @ayanakif7962 3 роки тому +4

    Comment section not dead even after 7 years

    • @breadedbread9022
      @breadedbread9022 3 роки тому +3

      People want a "Rational" explanation... I'm so sorry

  • @shakarwshyar2980
    @shakarwshyar2980 2 роки тому +2

    Thanks💕

  • @sheikhirshadsheikh
    @sheikhirshadsheikh 11 років тому +13

    Easy way of learning

    • @getit900
      @getit900 7 років тому

      Irshad Sheikh ģ

  • @christipotgieter9302
    @christipotgieter9302 5 років тому +2

    Guys!! Sal said "irrational numbers" like four times in a row(4:00). Great video, BTW

  • @bangtanarmy4546
    @bangtanarmy4546 2 роки тому +2

    Really Appreciate your work . 💯💯

  • @superduckmansuperduckman9504
    @superduckmansuperduckman9504 4 роки тому +2

    Yes thank you my online school is so dumb and does not teach me in a way I can understand this taught me more than the computer did which just expected me to understand

  • @praisejah4120
    @praisejah4120 5 років тому +4

    Thank you Khan for the hashtag, I was put into remedial classes recently and i started to believe Natural Selection, I felt my existence was simply to be inferior by nature . Telling me that gives me just confidence and motivation to work harder and catch up , I would like to make a difference in the world 🌎 one day . I’ll play an important role in making the quality of life better for all life , I won’t stop 🛑 😤

  • @ramkumarr1725
    @ramkumarr1725 Рік тому

    In this true world maths exists..❤❤🎉🎉

  • @joselynrodezno657
    @joselynrodezno657 5 років тому +5

    This was mad helpful!

  • @Stellajack04
    @Stellajack04 Рік тому +1

    Very simply explained. Thank you.

  • @hania6558
    @hania6558 Рік тому +3

    Why is his voice kinda...😍

  • @pinkymuktali5712
    @pinkymuktali5712 4 роки тому +2

    Nice teaching 👍👍👍👍👍👍👍

  • @sandipansen2760
    @sandipansen2760 9 років тому +3

    Thanks.This helped!

  • @saisai2173
    @saisai2173 2 роки тому +1

    You should be my maths teacher

  • @alhjooj2002
    @alhjooj2002 8 років тому +7

    thank you sooo much :)

  • @cadywhite2337
    @cadywhite2337 2 роки тому +1

    So helpful!! Even my own teachers say if I don’t understand it to look it up on khan academy 😂

  • @gamithadithya4166
    @gamithadithya4166 8 років тому +4

    thank you

  • @samalka.skakalka6786
    @samalka.skakalka6786 2 роки тому

    Hi I’m from Kazakhstan ( English is my 3rd language. I’m not native speaker ) and I understand this topic!

  • @ASMRkiddos
    @ASMRkiddos 8 років тому +5

    Thank you. :)

  • @umarshahidsahito9425
    @umarshahidsahito9425 4 місяці тому

    Your way us very precise. And you define the main thing that you've mentioned in the topic. You are teaching very nicely but i would request you to define other terms also. Just like if you are teaching rational number and you've mentioned the recurring decimals now let us know what is recurring decimal and how can it be found?

  • @robertcastaneda7562
    @robertcastaneda7562 4 роки тому +3

    My school teacher really did send me here during Corona

  • @yansong6923
    @yansong6923 4 роки тому +2

    I like maths its helping me lots its soooooo amazing

  • @vickysuleman1135
    @vickysuleman1135 8 років тому +47

    so what is a rational number...

  • @lizethvazquez7389
    @lizethvazquez7389 3 роки тому +1

    I understand this topic better thanks to this video

  • @chillz6793
    @chillz6793 8 років тому +4

    Lol he kept repeating each title like a thousand times! Thx really helped

  • @didadiy2548
    @didadiy2548 7 років тому +1

    thank you I like all you're videos

  • @azkasaqib408
    @azkasaqib408 4 роки тому +3

    7 years later this video has helped me pass my online exams during quarantine

  • @vanshchojar4642
    @vanshchojar4642 6 років тому +2

    I guess you should my math teacher

  • @ethangriffeth3679
    @ethangriffeth3679 5 років тому +9

    IM IN FIFTH GRADE Y'ALL

  • @sukjinahn2176
    @sukjinahn2176 Рік тому +1

    I think you are doing great job cheer up!

  • @gabys.cherry8148
    @gabys.cherry8148 7 років тому +35

    I really hate math and honestly I would rather have all my nails pulled out one by one than ever do math again but I have to do it and if I do it I might as well do it correctly

    • @SreenikethanI
      @SreenikethanI 7 років тому +2

      oh God
      chill

    • @chickennugget9742
      @chickennugget9742 5 років тому +3

      Why the nails though. Like...OW, how are you gonna scratch yourself?

    • @farah886
      @farah886 4 роки тому

      ouchhh

    • @farah886
      @farah886 4 роки тому

      Ayedan Moscal ouch at the thought of your nails being pulled out

    • @RaspberryV3
      @RaspberryV3 4 роки тому

      I would rather put a nail under my toenail, and smash that nail against a wall repeatedly, then stab a knife into my arm then do math again.

  • @KapilSharma-dj2qf
    @KapilSharma-dj2qf 4 роки тому +1

    it is very usefull,at the time of lockdown due to covid-19

  • @StrangeAngles
    @StrangeAngles 4 роки тому +3

    I appreciate your teaching style! Thank you!!!

  • @sonic_game_official
    @sonic_game_official Рік тому

    I'm learning 🤓

  • @arindammukherjee3965
    @arindammukherjee3965 6 років тому +3

    5x Irrational Numbers

  • @letschallenge6386
    @letschallenge6386 Рік тому

    This is best teacher of all time