Prime numbers | Factors and multiples | Pre-Algebra | Khan Academy

Поделиться
HTML-код
  • Опубликовано: 1 дек 2024

Комментарии • 450

  • @kpzcbttp
    @kpzcbttp 10 лет назад +98

    Thank you so much. I understand it now. I am 62 and I am trying to learn some of the stuff that I didn't quite understand when I was at school. My next step is algebra. Its not that I was stupid, as I was fine at other mathematics, it was the fact that the teacher we had for algebra was absolute rubbish at teaching. The whole class could not grasp what she was on about and we thought we were the ones that were thick. In those days (1966 in Scotland) they marked your work out of 100 and I can remember I got full marks for arithmetic and 80 out of 100 for geometry and a dismal 5 out of 100 for algebra, the rest of the class was just as bad. The class also excelled in chemistry, botany and biology but we still thought it was our fault that our algebra was a disgrace. Than God I didn't need algebra for my job as a personnel manager. I am retired now so I'm doing some more learning to prove a point to myself. Thank you for your help and your wonderful way of explaining things.

    • @romeostojka123
      @romeostojka123 10 лет назад +4

      why would 62 years old want to learn again math ? u already finish school that does not make any sense

    • @alectrobeat5
      @alectrobeat5 6 лет назад +5

      emporio armani hahaha I was thinking the same. I guess there’s never late to learn something new lol.

    • @lilly7619
      @lilly7619 5 лет назад +17

      @@romeostojka123 You use math everyday. you need to know.

    • @ryanprince3711
      @ryanprince3711 3 года назад +2

      Tempe:yes is does!

    • @ryanprince3711
      @ryanprince3711 3 года назад +1

      Tempe I agree with you Lilly!😁😁😁😁😀😁😁😁😁😁😁😁😁😁👍👍👍👍👍

  • @boldaer7619
    @boldaer7619 7 лет назад +55

    5:39 "We now know you could divide atoms, and, actually, if you do, you might create a nuclear explosion."
    I lolled so hard. That made my day.

  • @anhelicaalvarez5876
    @anhelicaalvarez5876 4 года назад +17

    You are awesome 👏🏼 You taught me a lot!!!
    Thanks to you I got my GED and I am now studying to become a nurse 👩‍⚕️

    • @vichilltime
      @vichilltime 4 года назад

      Why tho why now during covid

    • @aqua6014
      @aqua6014 3 года назад

      @@vichilltime i think its because she wants to and kinda has to

  • @jesselovell1241
    @jesselovell1241 9 лет назад +124

    Thanks for the video I am currently learning math for the first time because in school I didn't pay attention your vise helped a lot

  • @JYT.0120.7
    @JYT.0120.7 3 года назад +4

    You are a LIFE saver! My teacher was teaching me about this in online school and after math class i quickly looked up what are prime numbers and then i found your video! Thank you!

  • @mohammedhuzaifa9823
    @mohammedhuzaifa9823 4 года назад +8

    Thanks man 👍🤘🤙
    It made me easy after it 😊😁
    Love you bye 🤭❤😍😘🥰

  • @mmq6525
    @mmq6525 2 года назад +4

    i am a sophomore in college and i quite literally have never understood primes. (mostly because I never cared to) but I got a programming assignment to make a program that checks if a number is prime and I was having a ton of trouble understanding how to check if a number is prime by theory. A bunch of videos were useless in explaining the topic to me but you hit the nail on the head. Nice. Thanks

  • @andrewa626
    @andrewa626 11 лет назад +4

    You my good sir, Khan, are a hero! Thank you for teaching me prime numbers that others couldn't teach.

  • @sathwikaarmy
    @sathwikaarmy 5 дней назад +1

    THANK YOU AND FANTASTIC!

  • @TheSupermodel001
    @TheSupermodel001 13 лет назад +5

    Wow! Thank you for clarifying that. I didn't really get it the way it was explained in class, but you have definitely simplified this for me. Thank you. Your videos and teaching style usually make math really simple for me:)

  • @SuperMathmasters
    @SuperMathmasters 10 лет назад +45

    Think about Optimus Prime, Optimus is 7 letters and 7's a prime number O_O

  • @ieatpencils
    @ieatpencils 7 лет назад +15

    Loved this. Very easy to follow along. You've got a new subscriber.

  • @kermit368
    @kermit368 9 лет назад +8

    Wow I completely forgot about this...thanks for the refresh.

  • @rickyale
    @rickyale 12 лет назад +2

    Thank you! this is very clear to understand... prime numbers are hard to grasp the logic, especially when you come from poor education schools.. I learned prime numbers but I wasn't able to apply in personal use, I hope this video is leading me to really understand how to generate a formula or mechanism.

  • @NightsOfDevil
    @NightsOfDevil 11 месяцев назад +1

    Thank you, i appreciate ot so much you are good at teaching, well better then my teachers at school. You simplified this and gradually increase in difficulty, I understood very well. Have a nice day.

  • @glenmilner9828
    @glenmilner9828 4 года назад +1

    Yes! Thank you! Every other video on here complicate it by calling “natural numbers” factors. Now, my point being, if I’m here looking to find out what a prime number is, surely I won’t understand what a factor is! So where they fail, you win. And by saying “break the number down into parts” it makes a lot more sense. Thank you.

    • @bladeiron
      @bladeiron 2 года назад

      The curriculum that Khan Academy goes by teaches you about factors and multiples earlier on in the unit

  • @no-ch8wf
    @no-ch8wf 6 лет назад +3

    u just helped me with my homework lol i had no idea what prime numbers were!Your vid helped tho.

    • @kaydrawss5577
      @kaydrawss5577 3 года назад

      Hello fellow tokyo revengers fan

  • @Celoov
    @Celoov 5 лет назад +3

    What if we search for the numbers that can only be build by primes. Like 51. It's build by 3 times 17, which are both primes. Plot these evolved-primes (51 etc.) into the same graph that can show how numbers and primes turns into spirals and later strings when viewing from a bigger perspective.

  • @sannaarmy3499
    @sannaarmy3499 6 лет назад +2

    I have Georgia Milestones for tomorrow it’s the math part, and I’m reviewing thanks
    I also have a tip for prime numbers, my class just looks at the word. We like to see the “i” in “Prime” as “One”, then we look in front of the “i” And theres a “me” So we think as “me” As itself. So then it would be like ->
    Prime
    I+me
    Hope this helped!

  • @mimimokdad2405
    @mimimokdad2405 4 года назад +1

    THANK YOU SOO MUCH,YOU JUST TEACHER ME MY WHOLE LESSON THANK YOU SOO MUCH,I HAVE AN EXAM TOMMOROW AND THIS HELPED ME SO MUCH,I HAVE A PROBLEM TO UNDERSTAND THINGS QUICKLY BUT THIS IS REALLY THE FIRST VIDEO THAT ACTUALLY HELPED ME THANK U SOO MUCH 🥺🥺😭😭😍😍

    • @Kxriny_W
      @Kxriny_W 4 года назад +1

      9 years ago

  • @artdude13
    @artdude13 Год назад +1

    I had a state test today and there was a question about prime and composite numbers I did not under stand so I went home searched up prime and composite numbers and I found you guys and now I understand it

  • @piratelife6343
    @piratelife6343 9 лет назад +4

    Dude this is so cool!! Thank you for your videos man I'm learning so much! Peace and prosperity to you !

  • @aronbetterfr
    @aronbetterfr 4 года назад +19

    *who is here because they didnt listen to class*

  • @ObsidianSword-We-Da-Bomb
    @ObsidianSword-We-Da-Bomb 10 лет назад +17

    what's the drawing program you use

  • @BestUsernameEvaaaa
    @BestUsernameEvaaaa 11 лет назад +1

    I love this guy!!! thank you thank you thank you!!! i have been struggling with prime numbers for sooooooooo long i can't thank you enough!!!! :)

  • @ngocgiauhuynh8049
    @ngocgiauhuynh8049 5 лет назад +1

    thank you for this video, i was watching other vids and have no idea what's prime number is and this video helped me understand it well.

  • @_thanazure
    @_thanazure 9 лет назад +13

    Khan Academy
    best educational channel

  • @capteddie
    @capteddie 13 лет назад +2

    I'm enjoying your videos quite a bit. I'd love to see more info about prime numbers like different tests for prime numbers. Thanks!

  • @rhondaparker2955
    @rhondaparker2955 6 лет назад +3

    How does you write so neat on a computer? That is some neat work!

  • @sheepphic
    @sheepphic 7 лет назад +1

    You guys should do an abstract algebra course. It's really hard to find introductory info on the subject online, and it's essential for basically all of modern number theory

  • @abdelazizabdenim1697
    @abdelazizabdenim1697 3 года назад +1

    Wow, so honored! "THE FORMULAS OF NONPRIMES REVEALING ALL THE PRIME NUMBERS" was named one of the best new Arithmetic books by BookAuthority!

  • @chaitanyachandolu6039
    @chaitanyachandolu6039 8 лет назад +9

    thank you now i know about prime numbers

  • @melissaramirez9855
    @melissaramirez9855 8 лет назад +2

    this video helped me so much I understand prim numbers now thank you

  • @EyeIn_The_Sky
    @EyeIn_The_Sky 7 лет назад +5

    I wonder what annotation software you are using for this tutorial. Love the blackboard feel!

  • @StropSharp
    @StropSharp 9 лет назад +1

    Thanks for the vid very well put. I'm taking a basic math course and this is where I was lost. The only thing ringing in my mind was how much I hated this math in grade school and or high school and another course offered by a college( same stuff), either way these have always sucked ass. the only thing I can really say about them is they might help expand one's capacity to remember after playing with them for awhile. I'm glad we have them, otherwise there useless in my world.

  • @coolrobos284
    @coolrobos284 9 лет назад

    Thanks a lot... I searched many videos but didnt find them comfortable. Then I searched for Khan Academy and got it Thank you soo much. Jazakallahu Khairan.. ;)

  • @SharkFinn9090
    @SharkFinn9090 Год назад

    Thank you! I am starting in class and have a fear of asking question in front of people because they might think I'm stupid. But this has helped very much so I wanna thank you again.

  • @TheMrNomadus
    @TheMrNomadus 13 лет назад

    wooha wooha i've finished your cosmology course now now i don't even know now that course i guess. I'm gonna finish all of them. Thank ou Khan

  • @carlosmontijo6111
    @carlosmontijo6111 7 лет назад +1

    man u help me so much.
    you are my HERO

  • @fouadmajidi2568
    @fouadmajidi2568 3 года назад

    After wasting 6 years of school ( middle school and high school) without understanding anything in math here I am taking math classes because I need math in my Programming classes. Thanks, Mr. Khan

  • @virginiaw8608
    @virginiaw8608 3 года назад

    Ty. An example I could understand...30 years later I finally got it! Wow!

  • @queenforever4704
    @queenforever4704 4 года назад

    honestly, these videos help me a lot thanx for khan academy its a lifesaver

  • @Strolliosis
    @Strolliosis 12 лет назад

    No, it is divisible by 3, an easy way to know if it is divisible by 3 is to add up all the digits and if that number is divisible by 3 then the original number is too. For example 201 would be 2+0+1=3 or 123,456 would be 1+2+3+4+5+6=21 and 21 is divisible by 3 so 123,456 is also. but 856 is not since 8+5+6=19 and 19 is not divisible by 3. Hope that helped

  • @OMARYassin1
    @OMARYassin1 10 лет назад +2

    Really thanks
    Very very useful!!!!

  • @Swaggarafia
    @Swaggarafia 11 лет назад

    You know I never understood prime numbers. I could have raised my hand in class more but you know some students are actually insecure about that it this is one reason students suffer in advancing their academic growth. I'm glad I'm more clarified but something must be down to boost the confidence of students in class so their academic growth won't be jeopardized by their insecurity of not understanding something right off the bat. Future Einsteins of the World

  • @carolinewiggins7166
    @carolinewiggins7166 6 лет назад +2

    I'm studying for finals and this has saved me!

  • @Goldbergfan91
    @Goldbergfan91 13 лет назад +1

    When you went on to 6, I thought you were going to lay the seeds for Perfect Numbers. In the future, if you make a video on how to easily test if a number is prime or not, be sure to include the thing about the numbers square root, how you only need to test numbers up to (and including if the square root is an integer) the square root.

  • @AvivAtias
    @AvivAtias 13 лет назад

    @TheOkham I think very metaphorically they could be considered so.

  • @xoliswaskotha3889
    @xoliswaskotha3889 3 года назад

    Thanks sir your lesson about prime numbers really helped me a lot and I truly appreciate your great work.

  • @aliplays8143
    @aliplays8143 8 лет назад +2

    so Prime numbers are only odd numbers except 2 thanks dude ite really helped

  • @AhmedAli-xh9pm
    @AhmedAli-xh9pm 8 лет назад +2

    Thank you so much

  • @noxure
    @noxure 13 лет назад

    A quick trick to see if a number is dividable by 3 is adding up the decimals and see if the result is dividable by 3, works with every number.
    51 -> 5+1 = 6. dividable by 3.
    It also works with 9 (and 81)
    891 -> 8+9+1 = 18. dividable by 9.
    Funny thing is that this means that it doesn't matter what order the decimals are.
    198, 189, 981, 918 ,545454, 444555, 554454... can all be divided by 9.
    Take a number like 21, add some 3's and 9's in them: 2993333999391 and it's still dividable by 3.

  • @HasanAli-fb3di
    @HasanAli-fb3di 4 года назад +1

    The best Explanation

  • @jayasingherathnayake9220
    @jayasingherathnayake9220 7 лет назад +1

    You are so good at maths

  • @ikramulhaq5815
    @ikramulhaq5815 6 лет назад

    i understood a lot and iam preapering for my exams i understood prime numbers thankyou khan acadmey

  • @awsomenessgamer625
    @awsomenessgamer625 12 лет назад +1

    Thanks Sal!!
    It helped me alot on homework:P

  • @Queenofdarkness156
    @Queenofdarkness156 4 года назад

    Thx for the video for my math homework

  • @loganshaffer8956
    @loganshaffer8956 6 лет назад +4

    Thank you, I skipped class and forgot what prime numbers were. Thanks so much.

  • @Letsgetcreative-o9o
    @Letsgetcreative-o9o 10 месяцев назад

    They showed me your video on my online school.

  • @phoebechai5656
    @phoebechai5656 8 лет назад

    I am in in fourth grade and my mom made me a Khan academy account it is so cool

  • @AnisRidzwan
    @AnisRidzwan 11 лет назад

    Alhamdulillah,I understand what u r teaching but I really hope the next 2 weeks I still remember what's prime number.

  • @marshallhyasi6213
    @marshallhyasi6213 10 лет назад +4

    that really helped thx !!
    its kainda funny when you try to say divisible in a fast way ""dvvvisivvble"" LOOL
    THX AGAIN MAN !

  • @sagsol
    @sagsol 12 лет назад

    thanks a lot!!! i do understand them no so clearly, now I can teach it to my sister :D

  • @faredr1754
    @faredr1754 4 года назад

    this channel is very useful thx u

  • @ryanwochner6711
    @ryanwochner6711 11 лет назад +1

    Thx you have helped me alot on Homework thx to you I got an A+!!!!!!!Thx :)

  • @shazaduh
    @shazaduh 13 лет назад +1

    Thanks khan! can you do a proof of infinitude of prime numbers?

  • @Goldbergfan91
    @Goldbergfan91 13 лет назад

    @TheOkham Maybe. Depends on what you define addition and multiplication as under the vector space.

  • @sabsandtiffsproduction1719
    @sabsandtiffsproduction1719 9 лет назад

    It helped me a lot you explained much better then or math teacher lol thanks

  • @36gogo
    @36gogo 5 лет назад

    Got it !
    Thank you!

  • @أستغفرالله-ذ4ص7س
    @أستغفرالله-ذ4ص7س 8 месяцев назад

    thanks for you I understand it now ❤❤❤

  • @gplus46
    @gplus46 7 лет назад

    In school I didn't understand they whys about math, and so it didn't make sense. Now I see the importance of prime numbers

  • @innertubez
    @innertubez 8 лет назад +35

    791,159 views, that's prime!!

  • @ashfaquehossain8592
    @ashfaquehossain8592 10 лет назад

    exactly 2 natural numbers. This video is very helpful.

  • @oliviadubyu3150
    @oliviadubyu3150 4 года назад +2

    thanks for the help bro 🥶😈 🔥

  • @peNdantry
    @peNdantry 13 лет назад

    Thank you, Khanacademy! :)

  • @jacquelynedgeston8376
    @jacquelynedgeston8376 3 года назад

    Thanks for that I understand now 🙂

  • @Nool_-yo5ri
    @Nool_-yo5ri 8 лет назад +1

    this vid helped me a lot!!!!! thanks :)

  • @afroradiohead
    @afroradiohead 11 лет назад

    good luck. Even major rich education schools aren't familiar with prime to the extent your interested in it

  • @xxdexterrobotronxx2652
    @xxdexterrobotronxx2652 6 лет назад

    Very Helpful guys must try

  • @jordanmoore3413
    @jordanmoore3413 6 лет назад

    Thank you so much this HELPED

  • @BGood156
    @BGood156 13 лет назад

    @TheKturner05 I agree, some videos on number theory videos could be very interesting. It would also be a nice way to expose your audience to proof-based mathematics.

  • @Noor-tv6mv
    @Noor-tv6mv 4 года назад

    Very Helpful!
    Edit: Thank You

  • @theodorecraft718
    @theodorecraft718 11 лет назад

    thanks really really big help for my brother thank you!! :D

  • @mdhridoy4989
    @mdhridoy4989 7 лет назад

    very helpful

  • @mahamudkoranehirsi4115
    @mahamudkoranehirsi4115 7 лет назад

    Thanks to Khan Academy

  • @SamoanKiwi
    @SamoanKiwi 13 лет назад

    I never got it in as a teenager but i get it now as an adult. Irish i had you as a teacher

  • @danielkhachiyan5289
    @danielkhachiyan5289 10 лет назад

    I love this guy he helped me know haw to do prime numbers😘😎😎❤😊🌟

  • @icarorodrigo96
    @icarorodrigo96 Год назад

    Thank that really helped me to make a code

    • @jamlpe
      @jamlpe Год назад

      code for what?

  • @nazriniskandar
    @nazriniskandar 6 лет назад

    Thank you Khan Academy!

  • @exoticag7127
    @exoticag7127 3 года назад

    This video helps alot

  • @BladeEdgeShinobi
    @BladeEdgeShinobi 5 лет назад

    Thx khan

  • @wetlink0096
    @wetlink0096 4 года назад

    this helped thanks dude

  • @the1game50
    @the1game50 6 лет назад +1

    Hi bro. I found out two fonctions can generate prime number under 100. But over that numbers alot of constraintes should be considerated... too hard..what do you think

  • @dishonesttAbe
    @dishonesttAbe 13 лет назад

    Nice video Sal. Maybe you can do a video about the significance of prime numbers.

  • @robertodixonjr87
    @robertodixonjr87 12 лет назад

    Thank you i get it now finally

  • @brianjohnson7513
    @brianjohnson7513 4 года назад

    Should’ve been sub, you explain everything well

  • @cameronirvine323
    @cameronirvine323 10 лет назад +24

    Why didn't I watch this years ago?

    • @mushroomflow8499
      @mushroomflow8499 5 лет назад +2

      I'm watching this 4 years after your comment.
      Boo aliens in the future, booo

    • @horseflyer27272
      @horseflyer27272 5 лет назад +2

      @@mushroomflow8499 lol

  • @Chelsea-gn7tu
    @Chelsea-gn7tu 5 лет назад

    I finally understand what prime number is 👍🏼 yay

  • @SAVUFILMS
    @SAVUFILMS 4 года назад

    FINALLY AN EXPLANATION OF PRIME NUMBERS.

  • @3434emmanuel
    @3434emmanuel 11 лет назад

    thank you so much!