Number Trick - Numberphile

Just a quick number trick with Dr James Grime.
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[@richard_pine]

I went to try this, and the person said 8,888. And I said 1,111. Then they knew these weren't random, and she wasn't impressed.

[@AwesomeGamer00000]

You could respond 1112 or some thing like that but then just subtract one on the next number you put down but if it's the last number you could have already made a buffer on the middle number you put down.

[@TheSweBoo]

Your profile pic fits your comment so well :3

[@Evilm901]

Wtf?! I thought of 1111 too!! WIZARD!!

[@pratikkarnik5]

TheSweBoo and your profile pic fits your comment so well :3 :3

[@CollinInGame]

George Gyser you could have just done 0031 or something. It's the same value, just looks different.

[@dimmitsaras]

I noticed there was a scum going on with your numbers when i saw 22 responding to 77, which made me realise that your numbers werent random after that point.

[@cizma27]

Yes. I noticed too. And afterwards you just can't not see that they all add to 9

[@5gonza541]

Toni Krvavica Yea, it was pretty damn obvious

[@visansarma2534]

Hhhhb

[@asheep7797]

1-8 as well. 1 goes to 8 thrice in the trick.

[@ashfaqjuna]

Lol @ "scum" :)

[@cizma27]

I have a tip for you and for all those who are performing this. If your spectator's number has two or more same digits like (7721) it is kind of suspucious for you to write 2278. But in order to make it u suspicious you could for example substract 1000 from your number and write 1278. And then in the next step you add that 1000 to your number. You dont even have to add/sub that simple number. You could for example substract 1324 but then you just must add it to another number. And that's it. Simple tip to make this trick even better. I hope you like it

[@zymuur]

This assumes they will not choose 9 as the next start for their four numbers where you won't be able to add 1000.

[@cizma27]

right

[@MGShadow1989]

Toni Čizmić It doesn't matter what numbers they choose. They could put 9125, and all you would do is put 0874 - or, play around with the numbers and remember it in the next row. As long as your numbers add with theirs to create your intended total, it doesn't matter what numbers they use.

[@andrewsparkes8829]

Unless they do the double/triple/quadruple-digit thing as their own last number.

[@mdsharfuddinmd5710]

Thank you sir

[@alakadaspatnaik2830]

I knew this trick but never understood it, this guy made me understand it and have fun

[@gdibble]

3:08 "and you can look like a mathematical genius" XD

[@numberphile]

I feel like my Mum is telling me she is not angry, just disappointed!

[@createyourownfuture3840]

Wow! Numberphile only has 15 likes and no comments?

[@theuserings]

@@createyourownfuture3840 Amogus.

[@createyourownfuture3840]

@@theuserings please no

[@mdsharfuddinmd5710]

Thank you sir

[@EnglishRain]

I'm still at 0:08 and I paused to thumb you up for that amazing English accent!

[@selviegoenena8251]

Singapore pools

[@mdsharfuddinmd5710]

Thank you sir

[@DlcEnergy]

That was such an awesome, yet simple trick. If you don't explain it to someone, they'll be impressed because they won't know how you did it.

[@awesomex-uz7im]

Omg my old math teacher used to do this. He even once wagered his iphone and said if he is wrong he'll give it to the student😂

[@512TheWolf512]

oh, the math professor doesn't use an iPhone now i truly believe that he's and all-around smart man

[@anssiaurum264]

Don't know if this is sarcasm, but all he basically needed to do is subtract 2 and add 2000.

[@anssiaurum264]

+Kåpla Kvëhla *20000

[@512TheWolf512]

Chrnan6710 I wasn't trolling

[@Chrnan6710]

Eugene InLaw stop trying

[@512TheWolf512]

Chrnan6710 wtf are you talking about? Trying what?

[@greggwith3g]

This is fun - I like starting with a 4-digit number ending in 1 so that the resulting 5-digit sum has even fewer digits in common with the starting one, making the pattern harder to spot!

[@serzh0lozer]

Sir. you are magician!

[@numberphile]

If someone picked 9999 I'd do something like "oh being cheeky are you going for the biggest - just for that I'm picking 0000, ha ha"and make a little joke of it, etc!

[@ashumagicin]

I watched your some videos and all of them are interesting and full of knowledge. You and your team is awesome! Thanks for great videos.

[@mdsharfuddinmd5710]

Thank you sir

[@speedbird1598]

This guy looks like Fred Weasly

[@Mintymenty]

This is the happiest man ever

[@numberphile]

yes, though you need that control number at some point... I think the way James wrote it as an "example off the top of his head" conceals its purpose quite well and made it feel natural!? But the fun of these tricks is adapting them and making them better!

[@Sonuyadav-vf5kt]

Hii

[@BittuJassal-xc9qt]

Qz2

[@Noovil25]

Math doesn't always have to be mind-blowing,you could just sit back and enjoy the fact that numberphiles can always make tricks out of simple arithmetic,which I think is absolutely mind-blowing !

[@cartoon-mk]

Hy

[@knurlgnar24]

Stands in front of a giant chalkboard and says 'I am going to show you a number trick!' Proceeds to write it out on a strip of brown paper.

[@SupaDanteX]

Some other interesting things may include: If you square a number of ones, you get to count up and down based on how many you used. For example. 1x1 = 1 11x11 = 121 111x111 = 12321 1111x1111 = 1234321 ... ... 111111111x111111111=12345678987654321 And if you square a number ending in 5, you take the extra bit (n), multiply it by n+1, and then put 25 on the end (because the 5 in the ones place is 5x5=25) So for example. 35 x 35. n(3) +1 = 4. n(3) x n+1(4) = 12. So 35 x 35 = 12 (and then put the 25 on the end) 25. 35 x 35 = 1225. Or another example, 75 x 75. 7 + 1 = 8. 7 x 8 = 56 75 x 75 = 5625.

[@SupaDanteX]

And as long as the number ends in 5, I believe that works forever. Unlike the 1s, that stop working at 9 ones, since counting to 10 breaks it.

[@lam-yx5dm]

Kl trick

[@mdsharfuddinmd5710]

Thank you sir

[@numberphile]

Yes, HTC sent us 100 free phones and a a huge bag of unmarked £100 notes (with non sequential serial numbers) in exchange for showing their product in this video!

[@russellcastine2914]

I knew the answer before he added those numbers because I've seen this trick before! All you do is add a 2 to the starting number and subtract 2 from last digit, 3,485 becomes 23,483.

[@Shoutlikeatwebpunktd]

A few things about this trick are very obvious: When Brady said 77 and James wrote 22, it completely gave it away. You just had to look at the other numbers and you knew the trick. In the end it's also very obvious that the prediction is so similar to the first number James said. In general the trick isn't very fascinating because logically it is very obvious that you can just outweigh or compensate Brady's numbers with yours.

[@YogiliciousP]

Wow...I watched this a while back and it went right over my head. Now the while back was closer to the time when I suffered a concussion, actually a double concussion. Today I get it...totally simple too! I was having quite a difficult time with simple math...for example, military time is easy to do, sans a tbi. The midnight to noon are as is. The 1300 to 2359 are simple if you take the first two numbers, subtract 2, drop the first number if it's a 1 OR subtract 1 if it's a 2, and that's your hour, now just carry over the minutes. Alternatively, subtract 12, or 2 then 10. I not only couldn't do it, but I couldn't explain it. Ex: 1838 --> 18 - 2 = 16, drop the 1 in the tens place --> 6pm carry over the minutes --> 6:38pm. Ex: 2342 --> 23 - 2 = 21, now subtract 10 = 11, carry over minutes as is 11:42pm. I had expected to join the army and have spent the last several years with calendars and clocks in military time, expecting military time to become second nature...I still have to do the math jog. The math jog was what became second nature until I bumped my noggin!

[@cartoon-mk]

Hy

[@cartoon-mk]

Satta king single Jodi

[@cartoon-mk]

Hello bhai

[@numberphile]

no... I am actually really enjoying myself today! must get back to some editing though...

[@KittyRubz]

7 years

[@denfarc]

That was fun and interesting! Thanks for sharing :) 👍👍

[@vipgame705]

Singer Jodi lene ke liye WhatsApp🙏🙏👍👍👍👍👍👍🙏🙏🙏🙏 ok

[@noodlesthe1st]

too easy to figure out on the spot I think.

[@MyRealName]

you wouldn't believe

[@Kazoeru]

Lot of idiots to fool in this world, try it!

[@MANRAY_1]

noodles6669 I got everyone in my class by doing it

[@noodlesthe1st]

Ghostly Yoshi impressive.

[@MANRAY_1]

Dont Care we're the accelerated kids they just know how I am

[@gregharrison7497]

What happens if they pick 9886. To get 9 to 9 it's zero and If that's the first number then it's a 3 digit number and it spoils u

[@garnix5427]

where's the problem? the columns still give 9999 if you write down 0114.

[@Lucas-im9ly]

just pick 0114

[@NannaAshleyxD]

0113 would still count as four digits... just so happens that the first one is 0 :p

[@taneerhines8836]

fdddfgnjju

[@yuhunggoh7628]

Hey, that's what I was gonna say! GMNY

[@TheNimaid]

That's Numberwang!

[@KT-ut9zg]

Respect!

[@jimmyphone6688]

Lg

[@santoshmagar9161]

😂

[@IAmGpro]

That's just brilliant XD I wish more people knew how flexible math was

[@NikkiDoesStufff]

This dude looks like a Weasley who chose the muggle life and happily does mathematics for a living.

[@DRoo95]

The outcome DE...F can be written als 10000*D+1000*E+...+F = (9999+1)D+(999+1)E+...+F. As 9999, 999 etc. are all divisible by 9, the leftovers from dividing by 9 must be equal to D+E+...+F. So if DE...F is divisible by 9, so is D+E+...+F. (I thought this could be proven nicely using modular arithmetic but I don't have the knowledge for that.) So once knowing the mixed up version of the outcome, you just add each digit and figure out which digit you need to make the total divisible by 9. (2/2)

[@story46]

love it!! great stuff as always :)

[@numberphile]

In James' defence (this is edited out), he asked if he should add in his head or with calculator, and I said calculator because it just added another prop. Also (you allude to this, but don't agree) I think using the calculator better masks the trick itself, because the columns adding to nine is less likely to be revealed. (I can't claim that was deliberate - as I had not seen the trick before filming - it was all new to me) Calculator also adds a layer of "credibility" for the layman, no?

[@SameenKhan-oj5ig]

Ok

[@seangrand3885]

- You have a blackboard and a chalk. Numberphile: Yes. - Why are you writing on brown paper then? N: shut up!

[@gunjchowwiwat8357]

My high school friend used to play this trick with me. Today I just find out his trick!

[@KripalSahu-j4f]

Trik

[@DrEnginerd1]

Saw the 9's compliment a mile away.

[@3seven5seven1nine9]

Must've been a pretty big compliment

[@pakdhe8631]

Bos,kalo 6109_jadi berapa

[@pakdhe8631]

Saya mau menang lotre HK bales

[@sillysausage4549]

Yes, but are you happy?

[@mdsharfuddinmd5710]

Thank you sir

[@AbsoluteHuman]

The first number kinda reminds of the famous russian WW2 tank T-34-85... Don't say me that wasn't intentional!

[@drakwind9051]

Mind if I tell you instead?

[@juliak7654]

I knew how this would go as soon as he said they'll be taking turns now :D

[@MarioORSonic]

2 to the power of 31. Computers use bytes which are group of 8 bits. Bits have 2 states, on and off. and integer is made of 4 bytes. Since the first bit of the first byte is used to determine positive or negative. you are left with 8 + 8 + 8 + 7 = 31 bits left to use. 2^31.

[@vivavaldez87]

Is that what you're meant to say here? Trada? ... Good to know...

[@tomekgwozdz6037]

My family know that I’m into math and they can always instantly spot where is the math hidden in the trick. There is no fun with them at all

[@CratersAndCream]

I think it would be really awesome to hang out with Brady and James

[@mrshoeguy2477]

With this I can rule the world.

[@Chris_Tinacan]

This trick is gonna get me some serious poon.

[@adraedin]

Soooo... It's been four years or so. How much serious poon have you raked in with this trick?

[@mdsharfuddinmd5710]

Thank you sir

[@GGViraN]

I did it with my brother and he said 9921 so it became a 2 digit number

[@orphyn09]

I honestly got so excited when I saw he had upgraded from a crappy iPhone to the new and amazing HTC One! =)

[@xMegaVideos]

I like James, he always looks so happy.

[@jamesharrison7792]

What if the number one chooses happens to be 9999?

[@awildrengarappeared8419]

You tell him to say another one.

[@VSlimGoel]

I was thinking the exact same thing james harrison . but i made another similar trick with that. Ill take a number first row 6969 (lool I start) second row 9999 (ur choice) third row 1111 (my choice) fourth row 7875 (ur choice again) fifth row 3235 (my choice again) total is 29189 second row + third row have units that add up to 10 instead of nine so in that case my total number of those two rows would add up to 11110. i made the same rule apply for the fourth and the fifth row by making it add to 11110 making the four rows equal to 22220 and then add the random number of the first row that you've already predicted.

[@petersen341]

Vaibhav Goel If you add your units up to 10 in one row you could just add up to 8 in the next

[@VSlimGoel]

yea but the number 11110 is simpler. the point in mathematics is to usually keep the rules the same and not confuse yourself.

[@SquidofCubes]

you answer 0000

[@3DOrigamiandMore]

I love these videos!! I feel smarter every time I watch one!! :D

[@nxmeral328]

i already spotted the "oh im just gonna write a number that equals 9999 when added" thing at 7721 and 2278.

[@Sweetw4ter]

what you meant so say here is BAZINGA !

[@valentinrafael9201]

What if he picked 9999 TWICE?

[@leandronicolasea]

+Valentin Rafael run as quickly as you can

[@kurzackd]

+Valentin Rafael then you pick 0000 twice ;)))

[@michaelkim4142]

+Valentin Rafael Blow their mind even more by not adding another number. For example: I pick 3485 He picked 9999 I say pick again... he says 9999. I reveal my paper that says I predicted 23483 and wouldn't that be even crazier?

[@qtriss2354]

+Michael Kim what if he says 9999 then 9998, and you have to say 1? that'll be so obvious

[@mdsharfuddinmd5710]

Thank you sir

[@Omatecay]

Ok, here is importnat part that i feel should be in video. Giving number that add to 9999 can be quite easly spoted but giving one that adds to for exmaple 1027 and next to 1101 isnt so easy. Is little harder to do, but still nothing that you have to make pouse for.

[@kkgwen8837]

I already came up with this on my own. It’s a pretty easy concept

[@piprod01]

I figured it out before he added the numbers up. I did a similar trick to win the "Loves me..." multiplayer game in New Super Mario Bros. A flower has like 17 petals and each player can pull between 1 to 3 petals/ turn. Cycles "loves me"/ "loves me not" each time a petal is pulled. The player wins by picking the last petal on a "loves me" flower, or by avoiding, "loves me not". So if you go second you can force the opponent to pick the last flower by removing flowers to a multiple of 4.

[@nicolascrespo8638]

0:20 left hand Someone's been playing the bass

[@joslinnick]

I was thinking about this problem all day. It would look really suspicious if you were to pick a number starting with zero. The only 2 options I could think of would be to hope that the observer never picks a number with a 9 as a leading digit, of to explicitly state no to choose a number that starts with 9. Glad to see someone else was thinking the same thing.

[@thenoobalmighty8790]

Smash ur nan

[@Saerenn]

That's a funny trick,thank you for explaining it !

[@HaydenSmithElevate]

SAAMMME!!!! I watched that part 5 times in a row

[@lionkor98]

i figured it out at the very bginning... the 77 followed by the 22... just too obvious

[@dyrus5124]

Indeed.

[@3seven5seven1nine9]

What happened is after it was explained you thought "Ohh that's why they did that" and then "I thought that was weird when they did it, " "I figured it out when they did it," "So obvious"

[@Chiwun992]

1+1=2

[@tieb1407]

Wow

[@MrPatrickbuit]

2 + 2 = 4 - 1 that's three quick maths

[@lennartfriese]

MrPatrickbuit Everyday man's on the block

[@justealeksaite2000]

Lennart Friese smoke trees

[@osotanuki3359]

MrPatrickbuit 2+2 isn’t the same thing ad 4-1, 4 isn’t 3

[@vallov4188]

Oh thats cheeky

[@venkatbabu186]

We need numbers to construct the largest telescope of the world.

[@poojanainawat3890]

🙏🙏🙏👍

[@poojanainawat3890]

Hi😂

[@weiwei4962]

If i pick 9999 you can't do it XD

[@user-qb4xe2pr6y]

Wei Wei he can

[@weiwei4962]

Πανος Καλυβας how,since you can't say i pick 0000 beacause its so suspicious

[@user-qb4xe2pr6y]

Wei Wei i aggre with you but you dont know if you can pick 0000

[@Logjambam]

he would just let you pick a number again and only use four numbers because it already makes 9999

[@earlcayago3612]

Wei Wei yes he can. If you say 9999 then they can just skip doing a number since it already makes 9999 and there's no point of putting in a 0000

[@tsgoten]

James uses a HTC one!! Truly awesome

[@facebren]

Or write 1000. For the next number, you just make the first digits add up to 8

[@FanxB]

Some of your videos deal with advanced mathematical theory ... and this one isn't one of those. This is 2nd grade elementary school stuff.

[@The235Anil]

This one felt awfully simple, not like Numberphile. Don't like it.

[@marieq2431]

have fun going back to LionMaker then. lol

[@siprus]

Picking same number twice also does reveals the trick.

[@DRoo95]

Here's how it works: If you subtract the digits from a random number (AB...Z) the following happens: 10000A+10000B+...+1C-A-B-...-Z = 99999*A+9999B+... = 9(11111*A + 1111*B + ...). As you can see, the result will always divisible by 9, and so will the outcome of the multiplication be. (1/2)

[@gauravnegi2045]

very old boring trick

[@xamnition]

The classic "then why don't you do it better", please respond with something more original

[@eyesofphysics97]

Hey! for once, I got the trick before James explained it! Thanks to that comment that said that there was something fishy about the 22 and underneath it, 77

[@WhatSoEverThingsAreLovely]

You clevva little fukka you!! This pleases me greatly!! 💖

[@anticorncob6]

You specify: - The first digit cannot be a 9. - There cannot be two consecutive digits the same (5653 is okay, but not 5563). - There cannot be a fixed difference between them, such as 1234 or 3579. - You cannot repeat a two-digit set twice (3434 and 9292 are not allowed). With these restrictions, you can assure nothing of that sort will go wrong.

[@ulilulable]

A solution to this is to have a different total sum. 9999+1000=10999, which is the smallest sum you can add up towards that is "safe". So, basically, just tweak the method by doing the same with the three last digits as before, but make the sum of the largest digit be 10, not 9, and adjust the total sum beforehand. 10999+10999=21998, which means you add 22000 to the first number you pick, and then subtract 2 to get the final sum.

[@JAAT2363]

Dr r

[@hf27172]

I remember this trick from when I was a kid!

[@jjrubes1880]

i just watched a video on perfect numbers and the four digit perfect number is 8128, and in this video the fourth number shown was 8108 which is only missing root four in the tens column. And both 8108 and 8128 are divisible by four. This video has a very fourmidible, and strangely scientific connections.

[@chriswebster24]

It’s actually missing the cubed root of 8 in the tens column, or 4 squared plus 4 in the ones column, or root 400, or (my personal favorite), negative 49 plus…you guessed it….8 squared plus 5 💩

[@kaiwen4018]

AWESOME!

[@JackAsian]

I immediately what you were doing when you wrote the 3rd number when the 2nd and 3rd number in my head added up to 9999, as well as the 4th and 5th number.

[@henksteen9314]

This makes me happy!

[@lorenzoreyguitar]

Nice htc one you got there, happy to see you ditched that awful iPhone i saw on older videos...

[@tunawrangler1]

You could say "1812" then the next number is hopefully a 1-7 and then just add one to whatever you were gonna say.

[@rachadkoaik7647]

That way, if I correctly understood, you can even give the victim a choice of choosing the first number AND second number, u choose the third, he chooses the fourth and you choose the last. However the trick is to right the number you predict right after he chooses the first number. This will give the trick bonus points :) So if he chooses for example 7394 , you will write on the paper : 27392. :)

[@skate56994]

awesome video!

[@emmynoether5502]

Woah!!! Im totally gonna do this, and have a lot of fun freaking out my really dumb friends! Thanks so much!! : D!!!!!!!

[@z-beeblebrox]

Really, any 4 digit number where all the numbers are the same would break it, since it forces the presenter to also choose a 4 digit number that's all the same. If that doesn't make the person suspicious, they're REALLY not paying attention! Probably the best time to do this trick is in a bar after everyone's had a few drinks :P

[@TonboIV]

Very clever, but it's not just a trick! The 'Curta' was the smallest four function mechanical calculator ever made, except it could only actually add. To subtract it did this same trick, then added one and allowed the highest place value to overflow off the top of the register. Also, do you know what RPN is? If you don't, you should!

[@rishirajchauhan7592]

my father told when I was in 6th class. very nice trick

[@amazinggadgets6207]

At first I thought they were gonna stop using paper and use the chalkboard. lol

[@workforyouraims]

My dad told me this when i was a kid and that was the most amazing thing to me.

[@avnishhirani]

The HARDEST PUZZLE YET (type into KZbin, couldn't put web addresses) Try this James! This is guaranteed a hit on NumberPhile!

[@41570]

He used a calculator to make it seem he didn't know the answer. All part of the trick ;)

[@fredbach6039]

It was very easy to catch what you were doing when you picked your numbers.

[@sumantchopde9039]

Amazing!

[@3seven5seven1nine9]

To solve them using triple or double digits it's all about how you play it off. "Well, since you went triple numbers I think I will too," Also the game isn't necessarily 4 digit numbers, it's 4 digits. "0987" for example is perfectly viable, since they're jut digits

[@JayMark2049]

The point was that doing this will always result in numbers that are composed of the same repeating digit. 111111, 222222, 333333 etc.

[@callmejd_music]

I'm using Internet Explorer, I hope this comment does not come too late. Happy New Year 2012.

[@lythd]

I have a better one that uses a calculator and they chose every number. First you type in *+(0x(0* and then as long as you don't restart you're phone or close out the window (swiping it away not going to the home screen) u can turn u're phone on and open the calculator (it has to be the default one) and it looks normal but whatever they type will have no effect so just ask for some numbers that look like they'll make the number you chose and boom. Ik this is late but this video appeared again and I thought I might aswell share this. :D