Schools: *close* Michael: ...or do they???

@Kitsudote

4 жыл бұрын

*Vsauce music starts playing*

@Cowonahill_

4 жыл бұрын

Sh1pp0K1tsune It started playing before I even read your comment. X)

@TuhinBagh

4 жыл бұрын

DING!!!!!!!!!

@dewifrancis1299

4 жыл бұрын

My literal exams: Cancelled Michael: Or are they?

@dewifrancis1299

4 жыл бұрын

@@TuhinBagh dong

Schools: *close* Michael: Fine, I’ll do it myself

@xkilla911

4 жыл бұрын

this is a lesson on "discrete math" from college by the way.

@monkie2464

4 жыл бұрын

Fine, I'll do it BETTER myself*

@hellomine2849

3 жыл бұрын

ngl I learned new interesting stuff and I'm in high school

@-ahvilable-6654

3 жыл бұрын

He will not divide us

@user-cd4bx6uq1y

3 жыл бұрын

990 likes

Michael: Is 80 divisible by 4? Me: I don't know. Let me ask my French friends...

@gonderage

4 жыл бұрын

hon hon, it is la weed nombre.

4 жыл бұрын

Michel just missed a great opportunity to speak about ... you know, the big white Elephant in the room... THAT.

@user-xw4mu6nz4t

4 жыл бұрын

How to get your maths answer: 1. Ask any asian friend (preferably Chinese or Indian) 2. If that doesn't work ask your teacher... 3. You're in a test? Try and remember this video you watched 9 months ago 4. Wait... nvm I can just Google it...

@ashleybyrd2015

4 жыл бұрын

@@user-xw4mu6nz4t and if that doesn't work be inspired by the meet the engineer SFM and solve it with a gun, and if that don't work try more gun.

@gwenrees7594

4 жыл бұрын

Quatre-vingt ;)

BRO when I was in elementary school we did all of these except we got told “there’s no rule for divisible by 7” they LIED!!

@davidcole2913

4 жыл бұрын

No, it’s just that no one had come up with one back then. And honestly, the trick that Michael shows in this video isn’t a quick rule at all. Very time consuming. At that point it is faster to just divide the number by 7.

@thepriestunknown3999

3 жыл бұрын

15:38 here we are

@nitaibaishya6374

3 жыл бұрын

We were told that it was too critical for us so they excepted...

@jeffw1267

3 жыл бұрын

@@davidcole2913 I have a book from 1960 that shows a divisibility by 7 rule, though it's sort of complex. You have to match up six digits in the number to the series 132 645, working from the rightmost digit first. If your number is larger than six digits you start the 132 645 series again. Each digit in the series is multiplied by the corresponding number in the answer. For 362,880, working from the right, you'd get (1x0) + (3x8) + (2x8) + (6x2) + (4x6) + (5x3) = 91. Then you divide THAT by 7 and get a zero remainder. I think it's easier to just divide the number by 7 straight through, especially if you are doing the problem mentally.

@indigofenrir7236

3 жыл бұрын

@@jeffw1267 @jeffw1267 Double the last digit and subtract it from the remaining digits. Ex. 434 => 43 - 2(4) = 35, which is 7x5, so 434 is divisible by 7. Using Michael's method, 1/10(abc - c) - 2c 0.1abc - 0.1c - 2c 0.1abc - 2.1c 10(0.1abc - 2.1c) = abc - 21c 21c is just 7(3c), so it checks out.

The hero we need right now, but not the one we deserve...

@Equa11ysurl

4 жыл бұрын

Junior Studios Nobody truly deserves Michael..

@sean..L

4 жыл бұрын

why is it in past-tense?

@gumunduringigumundsson9344

4 жыл бұрын

Mister past tense there is probably feeling lonely. Be kind.

@ChristakyMe

4 жыл бұрын

deserve*

@kisaragiayami

4 жыл бұрын

Guðmundur Ingi Guðmundsson ok boomer

This turned into a math channel so progressively that I didn't even notice.

@danielmcdaniel1250

4 жыл бұрын

JJJ he’s literally numberphile rn

@cheesycheese60

4 жыл бұрын

It was supposed to be a channel with fun links in the description

@Ptaku93

4 жыл бұрын

@@cheesycheese60 maybe 5 years ago

@cheesycheese60

4 жыл бұрын

@@Ptaku93 u know time goes fast

@alevanderBatman

4 жыл бұрын

@@Ptaku93 Well... no. The name literally means "Do Online Now Guys".

Two types of people: Those who write '8' in a single stroke Those who draw two circles

@adamqazsedc

4 жыл бұрын

I draw 8 with a single stroke, obviously.

@squibble311

4 жыл бұрын

the 2 types are 1. those who write it in one stroke 2. michael david stevens

@TechnicFyre

4 жыл бұрын

It just comes out as nicer looking when you clearly make two circles. Unless they’re too far apart... or an accidental venn diagram...

@coltz-pun7871

4 жыл бұрын

What if I drew the two other halves of it

@possiple2126

4 жыл бұрын

I prefer to make a 3 and a backwards 3, please, I have standards

"Why Did They Change Math!? MATH IS MATH!" - Mr. Incredible.

Michael: "It's so important to unify, but today we're going to divide." *Starts multiple civil wars.*

@thenixaless7493

4 жыл бұрын

Yeet

@vividandlucid

4 жыл бұрын

Hey Vsauce, Michael here. As we all know, slave trade is unhumanitarian and unethical, and we should band together to abolish it. *Or should we?*

@hueban1643

4 жыл бұрын

fun fact: division in Swedish is called "bråk" which also means brawl or fight

@PuckishAngeI

4 жыл бұрын

Hey Vsauce, Michael here. You probably think that Iraqi government is stable and legitimate, well think again, there are multiple claims and today we are going to ignite them and see how many new countries will pop up on the map.

@TheEricwn

4 жыл бұрын

You mean divisible civil wars

Michael is starting to look like Charles Darwin with that beard

@thatladoverthere7075

4 жыл бұрын

Charles Manson*

@jellyman0127

4 жыл бұрын

Well, he is the next step in evolution for humankind.

@thedoctor855

4 жыл бұрын

Michael is Charles Darwin reincarnate

@VoiceDisasterNz

4 жыл бұрын

Or Friedrich Engels

@truediamant777

4 жыл бұрын

Yes he is almost ready for the prophecy

Vsauce is that one mad scientist that makes everything fun, but at the same time everyone suspects him of being on crack.

@noctusion2392

2 жыл бұрын

Same for Micheal Reeves tbh

@ActionJackson669

2 жыл бұрын

Maybe to people who have never seen a real crackhead before 😅💯

@whannabi

2 жыл бұрын

@@noctusion2392 nah it doesn't feels the same he's crazy in his own way

@matttaco

Жыл бұрын

wait he isn't on crack?

@hoseamathews5791

Жыл бұрын

​@@matttacoor is he

I've been using these divisibility rules my entire life in school and never knew how they worked. Who'd have thought that their functioning would be so easy to understand. Thanks Michael, very cool 👏👏

"divisibility rules" glad to see micheal sticking up for the underrated mathematical operation

@turtles10

4 жыл бұрын

lonely_ space_ egg I’m more of a fan of roots

@deaddead698

4 жыл бұрын

Tristen Roddenberry idk man it’s all about quadratics imo

@ihateroads7926

4 жыл бұрын

Pepper Mint Nah logarithms are where it’s at

@JonnesTT

4 жыл бұрын

Excuuuse you princess. Division is probably the most rad basic mathematical operation

@JonnesTT

4 жыл бұрын

@uwau cube root of 24 the 2.88th Reich :D

Michael looks like he already has been in quarantine for 5 months

@squibble311

4 жыл бұрын

he never met other humans, he was always in quarantine

@OceanRedux

4 жыл бұрын

BRUH LOL

@QuicksolutionsOnline

4 жыл бұрын

He was in prison

@Retard634

4 жыл бұрын

@@QuicksolutionsOnline based

@user-cu6yt1tr7h

4 жыл бұрын

actualy 12 years

Michael: Writes 1792 Ramanujan: *anger intensifies*

@aryarathod9192

3 жыл бұрын

Can you explain the joke please edit-I got it I guess he should have written 1729 because it is Hardy-Ramanujan number

@hhahah7263

2 жыл бұрын

?

@aryarathod9192

2 жыл бұрын

@@hhahah7263 it's a joke about hardy-ramanujan number which is 1729

@hhahah7263

2 жыл бұрын

@@aryarathod9192 idk what a hardy-ramanujan even is

@aryarathod9192

2 жыл бұрын

@@hhahah7263 It is the smallest number which can be expressed as the sum of two different cubes in two different ways

Thank you for explaining not only "how" more importantly "why".

11:46 “179200 I just made this one up” people he can create numbers he’s more powerful than we thought

@numberdcoool

4 жыл бұрын

Wat

@LeafShade

4 жыл бұрын

@@numberdcoool Until he made it, 179200 did not exist.

@joshuaslattery2416

4 жыл бұрын

@@LeafShade tbh i never thought about 179,200 before this video so id believe it.

@mathscienceonlineacademy4512

4 жыл бұрын

Exactly

@pikchassis

3 жыл бұрын

The other number was a decoy!

Michael looks like he's been isolated since way before this epidemic

@Megalomaniakaal

4 жыл бұрын

So do I tho. Oh wait. But I have been isolated for far longer. Never mind...

@vanzwho854

4 жыл бұрын

He has prepared for the random chimp event well. This man will leads us to victory against the chimps

@apersonontheinternet7607

4 жыл бұрын

Mind Field S1 E1.

@buttercopter9369

4 жыл бұрын

*pandemic

@macbeth8393

4 жыл бұрын

That would explain the 25 minute video on divisiblity rules... this man is clearly going insane

Mike: chooses 362,880 at "random" Me who watches numberphile: I see what u did there.

@shadrackbrentuo3665

3 жыл бұрын

???

@honeybee9455

3 жыл бұрын

@@shadrackbrentuo3665 the number has 160 divisors, is the factoral of 9, is a tau number, is pseudo perfect, etc.

@honeybee9455

3 жыл бұрын

@@shadrackbrentuo3665 basically all digits 1-9 are factors of 362880

@shadrackbrentuo3665

3 жыл бұрын

@@honeybee9455 Ooh. Thanks!

@honeybee9455

3 жыл бұрын

@@shadrackbrentuo3665 np

Divisibility by each number: 2: Number is even i.e. last digit is 2,4,6,8,0 3: Sum of digits is a multiple of 3 4: Last 2 digits divisible by 4 5: Last digit is a 5 or a 0 6: Number is even and Sum of digits is a multiple of 3 7: Take 5× last digit and add to remaining digits OR take 2× last digit and subtract from remaining digits. Final total divisible by 7 8: Last 3 digits are divisible by 8 9: Sum of digits is a multiple of 9 10: Last digit is a 0 11: Alternate between Adding/Subtracting digits from left to right starting with Subtracting. Final value is 0 or divisible by 11 12: Last 2 digits divisible by 4 AND Sum of digits is a multiple of 3

@It-b-Blair

Жыл бұрын

😮🤯

@natant927

3 ай бұрын

Why cant 6 * 2 be used to verify 12😭

@zafnas5222

3 ай бұрын

@@natant927 It's because 6 has a factor of 2 ie. 6 = 2 * 3. This means that if a number is divisible by 6 then it must be even so it doesn't make sense to repeat the divisibility by 2 rule

He's acting like he didn't leave us hanging for 7 months

@ckv954

4 жыл бұрын

- Leg1t Lmao

@peppermintmiso4341

4 жыл бұрын

He did have the holes one on Vsauce

@chugggs3516

4 жыл бұрын

Oh god I've just realized as well

There's a trick for 7 that's even easier: Separate the ones digit from the rest, double the ones digit, then subtract the 2 numbers. Here are some examples 903 separates into 90 and 3, double 3 to get 6, 90 - 6 = 84 which is divisible by 7. (903 = 7 x 129) 3171 separates into 317 and 1, double 1 to get 2, 317 - 2 = 315, which splits into 31 and 5, double 5 for 10, 31-10=21 which is divisible by 7. (3171 = 7 x 453) Note: If this process gives you 0, the original number is also divisible by 7

@MrGamingANDfootball

4 жыл бұрын

This is the one I know

@ireallydontknow3299

4 жыл бұрын

Oohhh, this is interesting. I suppose this is because adding -2 is the same as adding 5 modulo 7. As far as 7 is concerned, this is essentially the same as adding 5 times the last digit. Brilliant!

@angelmendez-rivera351

4 жыл бұрын

eventhorizon51 The reasoning is very similar. I am going to use three digits for the sake of simplicity for this proof, but it trivially generalizes to any number of digits larger than 2 via induction. Any 3-digit number is given by x = 100d(2) + 10d(1) + d(0), where d(i) is between 0 and 9 inclusive, except for d(2) excluding 0. The proposed method is 10d(2) + d(1) - 2d(0), but it works because 10d(2) + d(1) = (100d(2) + 10d(1))/10 = (100d(2) + 10d(1) + d(0) - d(0))/10 = (x - d(0))/10, and (x - d(0))/10 - 2d(0) = x/10 - 2.1d(0) = (x - 21d(0))/10, and 21 is divisible by 7.

@randomnpc445

4 жыл бұрын

This is also a much more useful shortcut if for some reason you don't have a calculator on hand. The one shown in the video is cool and all, but it's not very user friendly for larger numbers, not to mention having a bit of a complex process to it. This is a lot simpler and easier to follow.

@ireallydontknow3299

4 жыл бұрын

@@Aw3som3-117 I suppose only having to multiply by two will generate easier computations, so it might be slightly easier and faster than Michael's method.

1:36 "First let's pick a number completely at random" Michael lied as naturally as he breathed

@shivamchouhan5077

2 жыл бұрын

Literally 9!

There is something really cool in the inconsistency of Michael's writing. Sometimes he writes multiplication as an x and sometimes and dot. very cool.

@JanMilavec

4 жыл бұрын

he probs also holds the world record for the most ways to write an 8

Plot reveal : Michael is doing maths to avoid being crazy in his asylum

@cinnabonbon

4 жыл бұрын

Eh eh eh, no spoilers!

@TheBEST-eg4yd

4 жыл бұрын

MATH*

@OmarBKar-sw1ij

4 жыл бұрын

@@TheBEST-eg4yd It's called maths you American heathen

@ViratKohli-jj3wj

4 жыл бұрын

@@TheBEST-eg4yd It is called maths

@DanielDiaz-zz6ih

4 жыл бұрын

It'S cAlLeD MaFs! Words are words are words. Tyre and aeroplane are weird, though.

It took a pandemic to see him around again on this channel. Nostalgia for isolation Michael???

@grampton

4 жыл бұрын

Blue Shirt Wow bruh it didn't appear on my sub feed

@thealphas1

4 жыл бұрын

Damn we should have these pandemics more often

@spaghetti7929

4 жыл бұрын

it’s not nostalgia it’s trauma

@sy7028789

4 жыл бұрын

Not related message from a random Hongkonger for anyone watching: Remember the Virus is creating in China, it is all okay to call it China Virus. Never trust WHO cuz it is controlled by CCP.

Michael: Draws his 8 like that Everyone: Oooooooooooof no

@leavewe

3 жыл бұрын

what's wrong with his 8s lol

@spartanforce7

3 жыл бұрын

That's how they teach us to draw them in the Navy.

Michael thank you for all of your Vsauce, Mindfield and Ding videos! The content is some of the most fascinating stuff I've watched on the whole internet. Your method of presentation and your subtle humor makes for a really enjoyable experience.

I wish I could divide Michael so I could have a part of him

@davidsphere43

4 жыл бұрын

Who says you cant?

@deathbyseatoast8854

4 жыл бұрын

@@davidsphere43 mhm, yes fbi thats the man.

@thewj1228

4 жыл бұрын

Psycho

@noahgreer1497

4 жыл бұрын

Or would you? *que music*

@strbourne

4 жыл бұрын

I call dibs on the left foot

When Michael said that the random number is not actually a random number, I felt betrayed.

@Speed001

4 жыл бұрын

No number is truly random.

@hellomine2849

3 жыл бұрын

​@@Speed001 vsauce theme starts playing

@WWFYMN

3 жыл бұрын

@@Speed001 Or is it?

@theneoreformationist

3 жыл бұрын

I could tell by looking at it LOL

@ayaanshaheen6604

3 жыл бұрын

@@theneoreformationist It is 9! or factorial

In Divisibility with 7, I subtract 2 x (one's digit) instead of adding 5 x (one's digit). It is easy to calculate and works!

@A114N8D

3 жыл бұрын

Came here to say the same thing.

@inderchopra430

3 жыл бұрын

We can create multiple methods to solve the 7 one. Like multiplying unit digit by 1.5 and adding it to the rest should also work bcoz 1.5 - 0.1 is 1.4 But using whole numbers like 2 or 5 makes more sense I agree

@dorijanlendvaj8356

3 жыл бұрын

You can also, for example if the number is abcdefgh, look at h+3*g+2*f-e-3*d-2*c+b+3*a. Basically, going from the least significant to most significant digit you just repeat 1, 3, 2, -1, -3, -2. Much easier to do than the method shown in the video. As a bonus, all the other divisibility rules also preserve the remainder when divided by that number(for example, the sum of digits of 582 is 15 so it has a remainder of 6 when divided by 9). The rule for 7 shown in the video doesn't preserve the remainder, but this one does(but keep in mind that the remainder of -1 is 6, not 1).

This is the first time even in my life im watching a pure math video not because of school but because I wanted to... WOW, Michael really is powerful lmao

Michael: "In times like these, _we need to be _*_unified."_* Okay, how many people immediately said, _"Or _*_do_*_ we?"_

@OceanRedux

4 жыл бұрын

guilty as charged

@WildStar2002

4 жыл бұрын

@@OceanRedux me too!

@antonioocchipinti801

4 жыл бұрын

Ok I'm kinda embarassed to ask this but... so I'm pretty good at english becouse I'm learning it since I was 6 but I still don't understand what "Or do I" meme means

@WildStar2002

4 жыл бұрын

@@antonioocchipinti801 No need to be embarrassed about that! It's something Michael say A LOT in his videos. That's all! 😃 Watch a few more from VSauce and you'll see what we're talking about!

@onedarthyear726

4 жыл бұрын

antonio occhipinti the ‘or do i?’ meme uses sarcasm. Sarcasm is a type of humour that becomes funny by doing something unexpected. Like saying (insert random dictator here) did nothing wrong. The joke teller doesn’t think that that person did nothing wrong, but its so unexpected and rude that it becomes funny.

I love how earnest Michael is. Keep making the world a better place

@kfdhbdj9224

4 жыл бұрын

What is earnest?

@drdoof2940

4 жыл бұрын

@@kfdhbdj9224 ear·nest1 /ˈərnəst/ adjective resulting from or showing sincere and intense conviction. "an earnest student"

@LSK2K

4 жыл бұрын

@@drdoof2940 you use reddit by any chance?

I go back and watch this video over and over again simply because the explanations for how it all works is absolutely beautiful, and of course Michael talking about anything always makes it better too

Michael: Lets pick a random number also Michael: **picks a number divisible by all numbers 1 through 9**

@kickowegranie3200

4 жыл бұрын

he could have gone with smaller one, 7! (5040), it's also divisible into all the numbers 1-9 but it's much much smaller

@dzarko55

4 жыл бұрын

@@kickowegranie3200 Or an even smaller number, 7!/2.

@schrodinger6991

4 жыл бұрын

I think Micheal found the number himself and did not Google it. This is why he picked it I think.

@deidara_8598

4 жыл бұрын

@@kickowegranie3200 That is true, because 8 and 9 are not primes, and can thus be written has factors of the previous numbers, thus 7! is divisible by those as well.

@onemadscientist7305

4 жыл бұрын

@@dzarko55 which is the smallest (2520).

Me: Why does this work?? Teacher: bEcAuSe iT DoEs!! Michael: Weeelll. . .

@Rygir

4 жыл бұрын

That's not a teacher, or at least a terrible one

@hafda010

4 жыл бұрын

Шнат’s шітһ тһе шеігd теасһег сарітаls ?

@Real_Eggman

4 жыл бұрын

@@hafda010 Why are you writing in russian letters?

8:25 I was so looking forward for that moment to come, and when it did the song that kicks in when Michael says "or does it?" kicked in my head.

My favorite part of my Number Theory elective in college was proving the divisibility rules for 3 6 and 9. They seem so not math-y when you learn them as a kid, but the proof is very easy to understand

Just gonna leave this here: 10:18

@nickb8507

4 жыл бұрын

Bertil Johansson has oooh ooooooh 😫

@LeonStevenWilliam

4 жыл бұрын

20:23

@santicruz4012

4 жыл бұрын

Thank you

@zmirburger

4 жыл бұрын

thank you this has changed my life

@caritahearts2405

4 жыл бұрын

Vsauce out of context 4 babeyyy

D!ng dong Who’s there? Vsauce Vsauce who? Vsauce, Michael here

@br6768

4 жыл бұрын

Wasnt this channel called dong?

@claytonbyrd6134

4 жыл бұрын

@@br6768 it was, but KZread wasn't happy about it.

@aryyancarman705

4 жыл бұрын

@@br6768 what dong? It was never called dong, trust me..

@frostonium

4 жыл бұрын

@@aryyancarman705 it did kinda called dong something you can Do Online Now Guys Before it was reffering to uhhh the thing and its called ding now. I think anyways lol

@0bread286

4 жыл бұрын

frostonium He was joking. As though the channel once being called dong was something that couldn’t be talked about.

“It is so important that we social distance....” *Five Months Ago* Ahh yes how quick five months went

@Brindlebrother

3 жыл бұрын

isolation has increased the passage of time fivefold

@jeggehek6934

3 жыл бұрын

*3months ago*

@nates9778

3 жыл бұрын

@@jeggehek6934 and another one, another week down in the books :(

@m_e_nere

3 жыл бұрын

2021

Michael’s buttery smooth stream of consciousness teaching is absolutely god tier.

"I'm going to pick a random number"

@rmay2215

4 жыл бұрын

*it's casually divisible by all numbers from 1 to 10*

@alexandreman8601

4 жыл бұрын

@@rmay2215 it's casually 9!

@UnsIiced

4 жыл бұрын

@@alexandreman8601 It'S nOt NiNe ThOuGh

@alexandreman8601

4 жыл бұрын

@@UnsIiced it's 9 factorial

@FedeRama

4 жыл бұрын

"but what is random?" -Michael, 2014

Other youtubers: "Corona virus!" Clearly superior vsauce: "divisibility tricks"

@mrghostlyr1162

4 жыл бұрын

Yup, let's study to keep graduation possible (ahem homeschool) - internet available - free will available - no teacher peeking for rule breaking - school rules : no rules, games

@CRAIGC55

4 жыл бұрын

If people ate right they wouldn't have to worry about any virus.

@mrghostlyr1162

4 жыл бұрын

@@CRAIGC55 Well, then people must feed animals the right way, make special meal schedules, and redo the FRIKKING BIOLOGI, viruses are here because they are predictors too, imagine life 200 000 years ago but in the kingdom of bacteria, viruses, cells, whatever nothing has changed

@CRAIGC55

4 жыл бұрын

@@mrghostlyr1162 Viruses thrive off of bad cells. If you have been eating dirty for years, you will be a breeding ground for illness. If you remove the bad cells, virus has nowhere to live. Minimal place to live at best.

@noahwilliams8996

4 жыл бұрын

@@CRAIGC55 That's not how it works. At least not with corona virus. Corona virus will infect your cells regardless of whether they're "clean" or not.

This is exactly what I needed. The finals from last semester were delayed and they'll be soon, and this is a perfect way to remind myself about divisibility rules.

Nice explanation of the concept which I was looking for a long time, thank you so much for your time and effort.

10:18 I mean, come on. He just wants us to make memes.

I don't know if 49 is divisible by 7. Let me check that 4 + 9(5) -> 4 + 45 =49 Guess I'll never know

@june349

4 жыл бұрын

Know your 7 times tables, just like you should know your 8 times tables

@jamieg2427

4 жыл бұрын

o o o o o o o o o o o o o o o o o o o o o_ o o o o o o o o o o o o o o o o o o o o o_ o o o o o o o Seven rows and seven columns. Count the o's and then you've got 'em.

@Dziaji

4 жыл бұрын

Just keep doing the operation like Michael said to. It can take a while. Don’t give up!

@user-en7dx1qp3k

4 жыл бұрын

Do it the other way: 4 - 2*9 = -14

@gumunduringigumundsson9344

4 жыл бұрын

@@user-en7dx1qp3k that makes no sense at all lol.. you trolled my cranium there hahaha gj.

i turned this on while playing a game and didn't notice it was playing, I completely zoned out

Michael! I though of a way faster method to check divisibility by 7: 1. Take the leading two digits of the number. 2. Divide by 7 and find the remainder. 3. The remainder becomes the new leading term 4. Repeat until you recognize the number as divisible by 7 or not. E.g. 362,880: Not sure if divisible by 7 36->1 12,880: Not sure 12->5 5,880: Not sure 58->2 280: Pretty sure 28->0 0: Divisible by 7

8:26 At this point, I heard the music

@Andrew90046zero

4 жыл бұрын

me 2

@scmtuk3662

4 жыл бұрын

kzread.info/dash/bejne/hoJml8mhm8nNgaQ.html

Oily black man.

@2neutrino

4 жыл бұрын

Thus

@technoultimategaming2999

4 жыл бұрын

Ikr. I'd say Vsauce fits really well

@g.hmusicc

4 жыл бұрын

Technoultimategaming yeah with an intro like “hEy vsauce michael here!”, that sounds cool.

@whitetiger8115

4 жыл бұрын

Omg ur right it should

@Drozey710

4 жыл бұрын

I agree however he doesn't seem like the type of guy to have time to upload..

the fact that he writes 8 by drawing 2 circles unsettles me

i didnt know you made a video about my current math class subject thank you

Michael: "let's choose a random number" Michael: *choses 9!*

@softlysnowing3959

4 жыл бұрын

i know right

@caleblewis8169

4 жыл бұрын

He did it on purpose he winked i think

@softlysnowing3959

4 жыл бұрын

@@caleblewis8169 Of course, It's not like I didn't know I knew something fishy was going on.

@br6768

4 жыл бұрын

He writes 8's the same way I do!.. I always though I was weird but now I feel cool 😬

@brownah

4 жыл бұрын

Dwade : also chooses 9

"They allow us, in this lonely times, to make a bunch of new friends, math friends." --Michael, 2020

@tracyh5751

4 жыл бұрын

At first I thought he was talking about all of us watching this video together. More and more, I am convinced that Michael is talking about the math itself. The math is our new math friends.

@DucNguyen-rk8zu

4 жыл бұрын

Yes

I remember watching this when it came out. I didn't understand it back then but now after some algebra, and now calculus, This actually makes a lot of sense.

I got halfway through the video and Michael is showing us why these tricks work , I began to realize that this is how I do work in my head instead of writing it all down. this is the way I simplify the work so that I can do it in my head instead of having to work it all out on paper

I bet Micheal is powerful enough to know what happens when you divide by 0

@the_man_of_sex1427

4 жыл бұрын

Hi

@dysondyson9524

4 жыл бұрын

Le Rebel Flagship an error message

@renerpho

4 жыл бұрын

I've heard when you divide by 0, Chuck Norris appears and does a roundhouse kick.

@joshl90

4 жыл бұрын

Le Rebel Flagship it is infinity. You’ll learn about it in calculus when you go over limits

@oswurth8774

4 жыл бұрын

The answer is probably hidden in his beard

Not exactly a divisibility rule, but: To check if a number is prime, you only have to check all primes up to its square root. For example: is 103 prime? It’s square root is between 10 and 11, so check 2, 3, 5, and 7. We know it’s odd and doesn’t end in 5 or 0, and that 1+0+3 =4. The only one left is 7, which we test with the trick in the video: 10 + 5(3) = 25, so 103 is not divisible by 7 and is therefore prime.

@akkok5059

4 жыл бұрын

why do we check with 2,3,5,7? Sorry I'm not really good lol

@Waouben

4 жыл бұрын

@@akkok5059 First why do we only check divisibility with prime numbers? Because non prime numbers can be written as the product of prime numbers. Why is that? Because if your number is divisible by a non prime number, you can divide the factor once more until only prime numbers remain. For example, let's take 20. 20=2×10. But 10 is non prime which means you can divide it. 10=2×5. In the end, 20=2×2×5. You only need to check prime numbers to know if your number is prime. The only prime numbers below 10 are 2, 3, 5 and 7.

@Waouben

4 жыл бұрын

@@akkok5059 Secondly, why only check up to the square root? If your number is divisible you can write it as n×N, with n

@MrManiakKomputerowy

4 жыл бұрын

@@akkok5059 Because the rest of numbers between 1 and 10 are product of primes. Take the number 103 and check divisibility by 2, then 3. Now we have 4, but if the number is divisible by 4 then it's also divisible by 2 and we checked that already. Next comes 5, then 6 but if the number is divisible by 6 then it's also divisible by 2 and 3 - we checked that already.

I can literally watch this man explain anything for hours. I knew most of these tricks already, but still watched all the way through.

thank you! Your video is very explanatory. I like your sense of humor

19:22 "Oh! Look at this!" A new meme is born.

@lubomirkubasdQw4w9WgXcQ

4 жыл бұрын

Clever.

@nursmalik6024

4 жыл бұрын

I like how he went so crazy that he makes these reactions on calculations

"in times like these, we need to be unified, but today, were going to divide." *avengers music starts to play*

@Robbnlinzi

4 жыл бұрын

vevor jepo thanos wants to chat

Michael I just love your enthusiasm for the charity!

Helped my math, thanks Michael

Amateurs- "Number" Heroes- "Numerical" Legends- "Number in base 10" Michael- "Spelling of the number" (2:28)

@tap20

4 жыл бұрын

Spelling of the number in base (20/5) +(2*3)

@SLAMgamer11

4 жыл бұрын

Mathematicians - n, such that it is a member of a set R

@dhruvamehrotra1975

4 жыл бұрын

Well, technically they are digits.

@jackholmes7003

4 жыл бұрын

@@tap20 Base 12?

@luiginotcool

4 жыл бұрын

@@jackholmes7003 check again, it equals 10

Looks like I only knew a fraction of this topic.

@fawzanfawzi9993

4 жыл бұрын

Good pun

@chrisheli1

4 жыл бұрын

I don't have much to add here

@mlgepicbanana69

4 жыл бұрын

This made me laugh on *multiple* levels

@HI3Enjoyer

4 жыл бұрын

@Jacob Vachon no matter how hard you try to stop us all, there will always be a remainder...

Thank you Michael, this video helped me a lot.

I love your videos Michael Stevens, and I would like to say that I have learnt a lot of fun and exciting things from you.

@Dm3qXY

9 ай бұрын

stop calling him "Michael Stevens" , you're not his mom and he did nothing wrong...

just when i thought this channel would never see the light of day again

@afikanto4126

4 жыл бұрын

@@blueshirt1619 we are aware blue shirt. You no longer have to reply with this link anymore. Thank you for your service. -3-

Oh yeah! Michael is back OH NO, MICHAEL HAS BEEN LOCKED INSIDE FOR AN INDETERMINATE AMOUNT OF TIME

@bekeba

4 жыл бұрын

Flashbacks

@Kalay0Fox

4 жыл бұрын

chew

These help a lot more than you know in Permutation and Combinations!!

I was actually wondering a couple days ago why the division by 3 trick works. Nice.

Other integers: lmao just check if these digits are divisible 7: R E C U R S I O N

@angelmendez-rivera351

4 жыл бұрын

Actually, there are divisibility tests for 7 that are simpler provided you have a fixed number of digits to work with. For example, if I want to work with 3 digits, then any number will expressible as 100a + 10b + c. 98a + 7b will always be divisible by 7, because 98 is divisible by 7, since 98 = 70 + 28, and 28 is divisible by 7. Therefore, one only need check if 2a + 3b + c is divisible by 7 to check if your 3-digit number is divisible by 7. The problem is that this does not generalize as easily to any other number of digits. For example, if you want to check for 4 digits, as in 1000a + 100b + 10c + d, you instead have to check if 6a + 2b + 3c + d is divisible by 7. In other words, the quantity you have to check depends on the number of digits. This does not require recursion, but it trades for having infinitely many rules, one for each number of digits.

@melovepeas

4 жыл бұрын

@@angelmendez-rivera351 i was gonna say calm down its just a joke but that's actually a really cool point. It's not immediately obvious why 7 causes so many issues

@Bluedragon2513

4 жыл бұрын

A computer scientist's worst nightmare come alive

@onemadscientist7305

4 жыл бұрын

@@melovepeas The reason is that 7 is prime, and thus coprime with 10 (it shares no common factors with 10 other than 1). But, you say, it works with multiples of 3 ! And that's because 10 is 1 away from a multiple of three, which is actually a very special thing. Basically, there's no general rule... unless there is one. That is, it only works in special cases and in general you just have to go the recursive route. It's amazing how many things we take for granted about numbers when a lot of properties we think as intrinsic to the numbers themselves are actually dependent on the base being used.

@PTNLemay

4 жыл бұрын

7 is special boi

Relevant trivia: The number 2520 is the smallest number that's divisible by 1-10. Edit: It also has many other interesting properties such as being: - half of 7! (7 factorial) - a highly composite number (if you don't know what that is you may want to watch this video: kzread.info/dash/bejne/ZH6BlNGCncWfgco.html) - a colossally abundant number (I've tried to find and video or website that explains it in an understandable way but I can't find one) - a Harshad number (a number that is divisible by the sum of its digits. Ex. 24: 2+4=6, and 24 is divisible by 6) - the aliquot sum of 1080 (a rare relationship between two numbers where the sum of one of their factors is equal to the second number and the sum of the factors of the second number is equal to the first number. If I didn't explain it well I recommend watching until 1:30 of this video: kzread.info/dash/bejne/iaiWzaSlZ8baZKw.html)

@shoaibakhtar4389

4 жыл бұрын

Thanks for info friend

@shoaibakhtar4389

4 жыл бұрын

@@sy7028789 but i think this was a conspiracy theory 😅 isn't it bro?

@horizonkage

4 жыл бұрын

Math is broken. 2520 single digits should replace 1-10.

@woutervanr

4 жыл бұрын

I always approve of Numberphile videos. Especially after receiving my piece of pie yesterday :)

@Carbon_Crow

4 жыл бұрын

@Wouter vanR I prefer Tau over Pi but I kind of feel bad for Pi this year; nearly everyone forgot about Pi day because of the coronavirus Edit: grammar

I had know idea about the 3 divisible trick, thanks!

The number 9 always intrigued me

10:18 When she says, my parents aren't home.

@gumunduringigumundsson9344

4 жыл бұрын

🤣👍

@rjkzk

4 жыл бұрын

0:00 her doorbell after 0.1354 seconds

@JoniKauf

4 жыл бұрын

JS K (*≧m≦*)

@saulo4302

4 жыл бұрын

@@rjkzk If "That Guy" can help me out please, I'm trying to learn more about the english language. Technically that's not more than one second, so should it be "0.1354 second"?

I never thought I'd heard Michael say "Dong" again...

@RandomPlaysGames2763

Ай бұрын

Unlike the time he said "Ussie"

when he said "let's pick a completely random number" the number 69 was just written on his face

I love how simply he puts it. He could have made this way more complicated.

i learned a lot of these as a kid and one favorite pastime of mine is to mentally add the digits on license plate numbers to determine whether or not they're divisible by 9 (license plates in my country always have a 4 digit number in them)

@user-dt8mf8nt2v

4 жыл бұрын

I got quite confused by the "4 number digit" thing for a bit so I just wanna let you know you switched those around

@sharabhojha7895

4 жыл бұрын

Wait, so only 9999 people live in your country? There has to be some other combination of letters added in as well, right?

@edgarsxdwoo7417

4 жыл бұрын

yee in Latvia we have 4 numbers and 2 letters

@anzahanifathallah

4 жыл бұрын

@@sharabhojha7895 yeah the format is [one or two letters]-[four numbers]-[two or three letters]

@anzahanifathallah

4 жыл бұрын

@@user-dt8mf8nt2v right lol

_All aboard in Michael's online classes!_

@amgil475

4 жыл бұрын

D Sauce your name 😂😂😂😂

@averagemilffan

4 жыл бұрын

Kimi no na wa

Thank you, Michael. These are not good times for me, but you are making me smile every day.

I learned this in my senior year of high school (IB HL Math) up to 14. I love it sooooo much.

Michael: now let’s see if it’s divisible by four. My brain: oh yes, we can half it twice. Michael: take the first number in the two digit number and double then add it to the second digit. Me:...

@KaitouKaiju

4 жыл бұрын

If half the last two digits is even, then it's divisible by 4 Seems way more straightforward

@dylankrejci9965

4 жыл бұрын

@@KaitouKaiju that doesnt account for numbers like 16. 6/2=3 which isnt even. but as we know 16/2=8, and 8/2=4 so its even

@GRBtutorials

4 жыл бұрын

@@dylankrejci9965 It's the last two digits, not the last one. For 16, it'd be 16/2 = 8, which is even, so it's divisible by 4.

@steffen5121

4 жыл бұрын

Try dividing 426,421,295,739,292,069,436 twice in your head to check. I know it is divisible by four right away thanks to Michaels trick.

@TheArchoNils

4 жыл бұрын

@@steffen5121 You don't get it. You only half the last 2 numbers and check if it's even >___>

I´ve been practicing self isolation my whole life....

@emrekaraman6877

4 жыл бұрын

Gamer

@nolongerusing7430

4 жыл бұрын

same

@gabor6259

4 жыл бұрын

Introverts unite! Separately in our rooms. _(stolen comment)_

Michael is my perfect antidote to my technology-ruled existence

I cannot believe I've been taught calculus before learning why the divisibility rules work. Thank you Michael

I came here with a Popcorn I came out with a Mathematics Degree

@0bread286

4 жыл бұрын

No one, Duchi: *a* popcorn

@hachikiina

4 жыл бұрын

only one

@b0leg23

4 жыл бұрын

Shouldn't you say "went out"?

@saulo4302

4 жыл бұрын

Also, popcorn with a capital "P", which implies it's either someone's name, or a place's name. You can't carry a place around -or can you?- , so I guess they watched with a friend?

“4.9 looks a lot like 49, a number FAMOUSLY divisible by 7”. I guess yeah it’s famous. It’s the only number twice as divisible by 7 as any other number divisible by 7. I guess 49 IS famous in the circle of 7.

@Brenden-H

4 жыл бұрын

famous in the circle of 7? I think you mean.. in the SQUARE of 7. Ill show myself out...

@slimeypiston574

4 жыл бұрын

@@Brenden-H Ba dum tss!

@the_phoe

4 жыл бұрын

@@slimeypiston574 Well, the only number twice as divisible by seven as any other number divisible by seven before 2401 !!

Awesome, thanks for this!!!

Divisibility in base 6: *1* If the number ends in the ones place, then the number is divisible by 1. (same as 1 in base 10) 1:08 *2* If the number ends in 0, 2, or 4, then the number is divisible by 2. (same as 2 in base 10) 1:14 *3* If the number ends in 0 or 3, then the number is divisible by 3. (same as 5 in base 10, but replaced by 3) 1:17 *4* If the sum of the ones place digit and the double of the tens place digit is divisible by 4, then the number is divisible by 4. (same as 4 in base 10) 3:17 *5* If the sum of the digits is divisible by 5, then the number is divisible by 5. (same as 9 in base 10, but replaced by 5) 2:29

@Kai_On_Paws_4298

2 жыл бұрын

Good!

@coookieman334

2 жыл бұрын

best base

@subhradipporel9598

Жыл бұрын

what's the point j/k

@insanitycrafter8553

Жыл бұрын

Hi, I'm jan Misali, and-

@Dm3qXY

9 ай бұрын

is everything ok here? blink if in need for help

number theory , god they were the best 2 courses i ever took in the uni.

@Epinardscaramel

4 жыл бұрын

“I am dying to hear about it, since I always thought number theory was the Queen of Mathematics -- the purest branch of mathematic -- the one branch of mathematics which has No applications!” -Douglas Hofstadter, Gödel, Escher, Bach

For those of you who forgot the rules as soon as you stopped watching: 2: If the number is even, it can be divided by 2 3:Take all the digits in a given number and sum them up. If the resulting number is divisible by 3, the original number is divisible by 3 4: If the last 2 digits of the number form a number that is divisible by 4, the whole number is. OR. Take the 10s digit and double it, and then add to that the ones digit. If that number is divisible by 4, the original number is as well. 5: If the number ends in 0 or 5, it's divisible by 5 6: If the number is divisible by 3 and is even, it is divisible by 6 7: Take the 1s digit, and multiply it by 5. Then, add to it the remaining numbers as if it were its own number (the whole thing, not each individual digit). If the resulting number is divisible by 7, the original number is as well. 8: Take the hundreds digit, and multiply it by 4. To that, add the tens digit times 2. To that, add the ones digit. If the resulting number is divisible by 8, the original number is divisible by 8. 9: If the sum of all of the digits in a number is divisible by 9, the original number is divisible by 9 REMEMBER: All of these processes can be done multiple times if you are unsure if the resulting number is divisible by the number (1, 2, 3... ,9)

@Idisagreethisisnotanon

4 жыл бұрын

Matthew Riachi thank you soooo much!!

@xythrr

4 жыл бұрын

You forgot 1 help

@june349

4 жыл бұрын

@@xythrr Every number is divisible by 1

@softlysnowing3959

4 жыл бұрын

@@june349 Not True; Every Integer is divisible by 1, not every number

@june349

4 жыл бұрын

@@softlysnowing3959 I never said evenly divisible. I just said divisible

The way I was always taught to find a multiple of 7 is to double the last digit and subtract it from the rest of the number. 14 = 8 - 1 = 7 49 = 18 - 4 = 14 = 7 798 = 79 - 16 = 63 = 7

@skittybug6937

2 жыл бұрын

"63=7" Something here isn't adding up...

@chrisrj9871

2 жыл бұрын

@@skittybug6937 - 63 = 6 - (3 x 2 = 6) = 0, which technically works.

@skittybug6937

2 жыл бұрын

@@chrisrj9871 r/woosh

@Dm3qXY

9 ай бұрын

don't abuse the equal sign like that You can do this 7 | 63 "7 divides 63" or for the other way around, "63 dibisible by 7" i remember using in school three vertical dots like 63 :7 but with this unicode character VERTICAL ELLIPSIS (U+22EE) lookup the code. or like this 63 % 7 = 0 (modulo operation result )

@chrisrj9871

9 ай бұрын

​@@Dm3qXY - It would have been far too long to type what I wanted to say, and I'm just here for fun... I think it makes enough sense once the numbers get smaller.

This is the first explaination of math I understood. Because you explained "WHY and HOW" it worked.

3:27 the subtlest nod to the memers I've ever seen

@jeffireymurdock2073

3 жыл бұрын

Didnt notice 🤣

@Renteks-

3 жыл бұрын

not a clue what this was talking about