Lightning calculation and other "mathemagic" | Arthur Benjamin
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- Опубліковано 26 вер 2024
- www.ted.com In a lively show, mathemagician Arthur Benjamin races a team of calculators to figure out 3-digit squares, solves another massive mental equation and guesses a few birthdays. How does he do it? He'll tell you.
TEDTalks is a daily video podcast of the best talks and performances from the TED Conference, where the world's leading thinkers and doers are invited to give the talk of their lives in 18 minutes -- including speakers such as Jill Bolte Taylor, Sir Ken Robinson, Hans Rosling, Al Gore and Arthur Benjamin. TED stands for Technology, Entertainment, and Design, and TEDTalks cover these topics as well as science, business, politics and the arts. Watch the Top 10 TEDTalks on TED.com, at
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I've never rooted so hard for someone to do a math problem.
That cracked me up
*****
I was thinking the same thing. It was very suspenseful, like close soccer game.
I would watch mathematician competitions on TV, lol
@@escargoux whoosh
Hahahaha rooted
This guy's pre-frontal cortex must be a quad-core.
his brain is a supercomputer
+Durzo heh... Well Damn..
Durzo It's as simple as he has more blood flow to his brain than the average person.
octa core!
r/iamverysmart
teacher: no calculators allowed in tests
me: brings arthur benjamin
teacher:
Oh, the days before everyone had a calculator on their phones.
More than just impressive, he seems like a genuinely great guy, great humor.
A fantastic guy. Really deserves a standing ovation.
He got one at the end of this video!
loved it when he showed no problems in revealing his methods. Amazing!! Dam good!!!
Damn
I just love this guy. He's incredible.
My sister has his "the Great Courses: The Secrets of Mental Math" She is absolutely amazing! She can finally square 5-digit numbers in her head, though it takes roughly 2-3 minutes.
*****
sarcasm?lool
Wow you're so classy... She goes to math competitions and wins, thank you. That's how she applies this knowledge.
Well that's obvious, but for now, it's quite useful...
@@isabellajimenez7072 are you still there mate
This guy is great! it's one thing to be a math genius...it's another to know how to work a crowd.Seriously, the way he keeps the audience enthralled and inserts light humour "Let me re-cap *puts cap back on*" is a great way to ease the audience.Wow. Great Going Art :)
1:27 He almost said the word stupid
+ThePlayersPlay Lol
+ThePlayersPlay Oh My god! Yes ! LOL
He was about to tell 624 i think so....
true
STU- 594!!!! Give her a round of applause!
What I liked about this that the guy was actually funny.
You wouldn't expect it from this kind of person.
Very good!
Oops, I see a carry coming.
Saw this live today, he came to our school and he truly is amazing!!! Amazing work !!!!
When he asked the audience what 5 squared was, I blurted out the wrong answer..
😂😂😂
Ok boomer
David Weng you’re using it wrong...
Chen H would you be so nice as to teach me then?????
David Weng It’s not funny regardless of how you use it. But it’s especially not funny when it makes literally no sense, like how you just used it.
It's a mind blowing application of the (a+b)^2 and (a-b)^2 formulas.
Still a damn genius.
I got the book.
He's phenomenal!
Interestingly, in the trick, 8649 is a multiple of 9 which means that any multiple of it will also be a multiple of 9. The test for divisibility for nine is that all the digits added will still give a multiple of 9 if done recursively and so we can just add the remainders with 9. (ie. 81(8+1) , 8649 ( 8+6+4+9 = 27, 2+7 = 9) . We don't have to even go this far in addition. We can keep subtracting 9 as the sum becomes greater than 9 and that's all he does with his showmanship of course, eg.
He took 8649 because it was convenient,
(he says six digits in "any order" because the order of the sum of the digits hardly matters. A middle school student knows this.
person 1 -1,9,7,0,4,0 - (find the sum subtracting 9 every time the sum exceeds 9 and you get 3 - so the number to be added to this to reach 9 would be 6 and that's what he says.
person 2 - 4,4,8,7,5,2 - circular sum = 3 therefore answer = 6
Person 3 - 0,7,9,0,4,4 - circular sum = 6 . Ans = 3
Person 4 - 2,6,3,9,7,2 - circular sum = 2. Ans = 7.
Loved the way he pulled off a middle school question with all that showmanship.
Nice work figuring this out! I was hoping the comments would contain something like this.
aanand srinivas Yeah I go that too. Nice trick though
aanand srinivas didn't even get this
It is not a random coincidence that 8649 is a multiple of 9, either. The way he got these numbers was by calling 4 people in a row, with the last being on the end. He did the exact same procedure in another video I've seen him do this trick. Again, the last choice was a girl on the end of the row who served him up a number divisible by 9. This is a trick which I think is beneath this man. All of the other calculations he does are completely legitimate and can be learned from. This trick only works when his "plant" in the audience serves him up a number divisible by 9.
an easier way dude, is to just add all the numbers, and subtract it from the next multiple of 9. example: 1 + 9 + 7 + 4 + 0 + 0 = 21. 27 - 21 (next multiple of 9) = 6.
Art, you rock! Art Benjamin is a professor where I went to college, Harvey Mudd College. Despite knowing him for years, I am still in awe at his mental math ability.
I don't know if this is how he did the missing digits trick or if it was just a coincidence: the number he chose, 8649 is divisible by 9 and I know this because if you add all the digits, you get 27 which is 9*3. The is the divisibility rule for any multiple of 9. If you multiply 8649 by a 3 digit number, it will still be a multiple of 9 and thus the rule still applies. For example, if they told you that 6 digits were all 1's, then you would know that the last digit is a 3.
That's exactly what he did. Notice how he picks the one number that is divisible by 9. The day of the week thing he uses an algorithm for, though he said 1824 is hard implying he's using "anchor dates," which is really inefficient imo, there are better ways.
The three digit squares he talks about in his book, and he's so well versed in it it becomes almost lightning like.
Ray Chou
Might have been because 1824 was a leap year
This is just like knowing all the necessary moves to manipulate a Rubric cube, then practise practise practise.
Truly appreciate Arthur Benjamin's efficiency, intelligence and eloquence. Thanks for sharing this video. Best wishes.
My class invites you to our school. I have showed this video so many times to so many classes. Every year my students are amazed. Some of them say you are their idol because of your mental math skills.
Nice viewing.. But two mistakes
457^2 = 208849 [Not 208549],
722^2 = 521284 [Not 513284]
I guess the people with the calculators on stage doubted themselves / were embarassed to point it out.
But still amazing to do this in so short a time.
For 457 squared I heard him say 205849 but my calculator gives me 208849.
Were the people with the calculators retards or something, couldn't read out the correct answer or were too shy to correct him.
Anyhow, his performance is still absolutely remarkable as he only did two mistakes in over 50 calculations
I was impressed... yes with "the show/ presentation" but more so, how fast my 2kids picked up mental math as a game. You gotta get this guys book! It makes math very "useful" for everyone. I wonder why schools have not picked up some of his methodology. It is so musch easier than how traditional math is tought. When you look past the showmanship of this video, there is real science, genious, and surprisingly FUN. Very impressive Mr. Benjamin. Best of luck to you.
"someone give me a 3-digit number."
"100."
Thousands still do it in India. Shakuntala Devi is a famous and much venerated Indian mathematician who is considered a genius and is popularly known as the Human Computer. In 1977, Shakuntala extracted the 23rd root of a 201-digit number mentally, 12 seconds faster than the Univac-1108. She even occupies a place on the 1995 Guinness Book of Records for her skills.
This is so awesome, I am really at awe. I''ve bought his book before I saw this video, now I'm gonna read it
how is your mental calculation ability now?
HOW YOU DOIN COMRADE ?
This show's script if identical to his Ted talk 5 years later it's almost insane. I can't believe he did the exact same show over and over for that long.
First I said: wow he is a math genius. Then I said: wow he is a time traveler.
This guy is my math teacher at Mudd. He's awesome.
Wow, amazing! He's well articulated, talented, and entertaining as hell.
The first time I remember seeing this video was in my pre-calc class junior year of high school back in 2010-'11. The video is so good that I keep coming back to it now several years since I finished school.
He must have eaten a calculator when he is 1 year's old
😂😂😂😂😂😂
Did u eat a joke book when you were 1 year’s old
This was amazing to watch. - Definitely not the same as this video, but sometimes I give my son math problems just on a whim to solve, and I gave him 97+49 ...He gave me the answer from his head before I could. :P He's 7. lol You would think I'd be embarrassed to tell that story, but nope. Too proud of him to care. :P If he's a natural mathematician, I will definitely support and encourage his development in that subject.
I get a hint this gentleman is good at maths. Just a hint though...
Watched this in Math Club and my seat mate who was a fast calculator was mind-blown.
Lol, same exact thing in another TEDx Talk
Agreed. Makes me wish I enjoyed algebra more in school.
He is great in mental math, there is no question about that. I had that experience when I was in grade 5 in China. wht i remember was doing addition and subtraction instead of multiplication, nothing very tricky, coz u still have to memorize all the procedures and number in it.
Biologicalscum - when he says "cookie fishin" he is referring to 77862. When he says "revup" he's referring to 489. I don't understand when he says "there is a cary coming". The mnemonic system he used is explained in a book by Tony Buzan - Master Your Memory. You'll have to buy another book for mental arithematics...
I actually watched this clip more than twice.
Ann Cervales more than twice? You can't count higher than that?
This is very easy one. He has a partner in the audience with a calculator. In his right ear he has a transmitter and a receiver. He gets the answers from his partner. Its hard to tell, who he is. The ending with the five digit square, he just puts a show and makes it look like he does the math. David Copperfield had a similar trick 10 years ago in Vegas, but he took it of his show because people guessed it how he did it. People knew him as a magician, and not mathematician.
Robert Pistone
You have no idea how wrong you are
8:00 For day of the week trick
The people on stage don't know how to use their calculators. Even when he's wrong they say he's right.
457 ^ 2 = 208,849, not 205,849
722 ^ 2 = 521,284, not 513,284
He did square the four digit number correctly. I'm impressed.
This guy shows some amazing abilities, but can he take out the trash ?
lool
I just saw this guy on the Colbert Report lol
He's pretty damn cool!
everybody in the audience are in on it.
as a senior in high school, i can also tell you that your typical high school that all the middle-aged people have grown up in, has been in a single word, disintegrated. Im top of my class at conrad weiser high school, and this has not hindered my ability in any way.. Im a nerd, proud to be one.. There's a saying, "you can call me nerd today, but boss tomorrow." Girls know this too.. @Oli978Oli978
A few weeks ago I attempted to multiply a 4-digit number by a 2-digit number... in my dream. I actually remembered my way of calculating it when I woke up and it was correct, but it wasn't finished, unfortunately
+KonstantinGeist I think dreams could be used as powerful tools if we practice it. ("Practice dreaming?" - I don't know if you're familiar with lucid dreams, but it's where in a dream you KNOW you're dreaming. Therefore could do practically anything you want.) In one of mine, I could speak and understand fluent French. Like it was the most natural thing to do. It'd be amazing if we could tap into this ability. : )
Opal SeekingtheTruth I love that concept! I would recall things that I had forgotten(while awake), in my dreams. There has to be a way to tap into our subconscious and draw out ideas, thoughts, memories, data, etc...
This guy is so good. Definitely, definitely.
"let me re-cap"....... ahhaah lol nice one. XD
This guy inspires me to be good at math
I like him, he's so smart and funny as well!
+Ann Cervales are you attracted to him sexually or just like we men are amazed how he is good
Of course not sexually! Lol
+pako pako That's a nice thing to say to someone.. :/
He did pretty much the exact same thing in a Ted (might have been TedX) talk many years later. Same words and everything, just different numbers haha
One mistake sir, 1824, June , 6th was actually sunny ⛅.
Lol
I am not undermining his immense genius, but for anyone who didn't know, this is the theory behind his 5-digit problem.
57683 x 57683 OR a^2
1) 57683 = 57000 + 683 OR a+b
2) (a+b)^2 = a^2 + 2ab + b^2 (first identity in algebra)
3) 57683^2 = (57000+683)^2 = 57000^2 + 2*57000*683 + 683^2
Now the rest is pure brain-power, but I hope this simplifies things somewhat. ;)
at 3:42 he made a mistake... 457^2 is 208849 and not 205849 as he said!
Yeah!
Yeah! The 4 guys in the platform had some gestures like disagreeing with him, but he didn't mind. But this it's just a little mistake. ^^
Also 722
Sounds right, These guys put so much work into a small tricks like this.
Me returns from grocery store
Mom: where is the remaining money?
Me: 13:56
Interestingly none of these tricks are actually that hard with practice. Not only that but Arthur Benjamin published how to do all of these tricks online in 2004 (google squaring three digit numbers, first result). Why does this man still have a job then? I guess showmanship truly is everything to the magician.
I need him as my next math teacher...
If i was in the audience and asked to give him a 3-5 digit number, i'd make it a 2^n number just for fun.
"you there on the third row, give me a 4-digit number", "1024", "haha, good one, 2^10 squared = 2^20 = 1048576".
Since it's at TED, at least 10% of the audience would get the joke, and probably a lot of them would be able to do the square in their head too :P
It could also have been fun to give him the first 3-5 digits of pi :)
What if someone had left out 0 or 9?
It's not as simple as the original number ending in 9. It wouldn't work with 8349, for example. It is more specifically that the original number is DIVISIBLE by 9 (the sum of its digits is 27). Therefore any number times it is also divisible by 9. Then the procedure is to simply add the digits and figure how far to the nearest 9.
This is insane. I was actually going to bed. then I thought, lets watch a TED talk. I am fresh now.
*Standing Ovation*
he got two of the 3 digit squares wrong (and somehow the people with calculators didn't notice)
457^2 is equal to 208,849 not 205,849
722^2 is equal to 521,284 not 513,284
why no one ever pick zero?
Probabaly Mavadd, but that is where the genius comes in...the capability to create such a unique system that works for you...That capability to me is pure genius
"It will take me a little bit of time" it would take me a year.
Hvis du har brug for hjælp bare besked mig om WhatsApp på +63953150922
Na, you can easily calculate all the stuff he was doing.
The day of the week trick is very easy to learn, took me like 4 hours of practice when i was 7 years old.
SUPER awesome bar trick :)
722^2=521284 and not as he claimed 113284 4:01
rubic64 You mean "as he claimed 513284" but you're right! He got it wrong!!??
And the first 3-digit number he also got it wrong
987 squared does equal 974169
Sorry, I meant the second one.
457^2 = 208,849
He said 205,849
+Grejegando he said it wrong. The rest were the same.
Just awesome.
what happened to cookie though .did anyone eat it🤭🤭🤭
the trick at 7:00 is that 8649 is a multiple of 9, so you can multiply it by anything you want, the sum of the digits of the result will be a multiple of 9. So he knows witch digit they don't say... The problem would have been if there was a 9 or a 0, and if that was the number they didn't say :p
Mother of MATH !!!!!!!!!!!!!!
Although I typically frown strongly upon the typical math magic I've seen, I can't help but appreciate the work that this man does and the show that he puts on. Numbers are simple, and with practice, observation, and motivation, It's not surprising that this can be done. There are many unobserved patterns and unpopularized formulas that can make these calculations relatively simple. I am not surprised, and barely impressed, but I am very appreciative of the interest and practice behind it all.
His intro: Exact same wording he used at our assembly today. :O
@siddharthjoshi91. The remainder should be your answer. For example- if the six digits are 3,6,4,2,2,9 the addition is 26. Subtract 26 from 27 to get 1.and it is indeed the answer
No magics just mathematics.
Jordan Rogerson well, most of these routines are described in mentalism books...
The kind of guy you want at a Ted talk, not tge guy you want at a party
he is a human calculator
nothing beats him
I like the phrase the improbable
no lah I copied u
awesome
***** he is a real man
Lets pit him against my 4090 in tensor calculations
The missing digit trick and the day of the week is actually pretty easy to learn when you know how it's done. The squaring on the other hand will take most people years if not decades to learn.
3:41 he's asked about 457*457 and he says 205,849... btut it's actually 208,849
I love your username.
back in the day it use to be 205,849 , then they updated maths
Nobody's perfect
i cant even do a double digit and this guy is......no words, simply amazing
damm killer cpu
i was priviliged to see arty live a few times, he is very entertaining,
the answer for 722 squared was actually wrong.
Still can't deny he's amazing!
I salute this man,,,he's so smart!
He just visited our school! :D
AMAZINGGG
A matemática e a sensação de prazer logo após resolver um grande problema matemático, me fizeram recuperar a auto-estima e sair da depressão.
Inglesa por favor
my math teacher was in a conference with Arthur Benjamin and beat him at the 24 game
3:43 457 squared is 208849 not 205849
I am pretty decent at squaring 1 digit numbers in my head myself :)
No discredit to Arthur but it's crazy to think that there have been mental calculators who were able to multiple a lot larger numbers a lot faster.
How am I JUST seeing this!?! He's not only Brilliant, he's HILARIOUS! Thank you Arthur Benjamin!
"Try to square your views modafucka!"
- "... 479236368361 and after?"
Fun fact: He'll get bank cashier's job
Art Benjamin was a member of the Pi Lambda Phi fraternity at Carnegie Mellon University.
Woow this genius Hope he swallowed a scientific calculator.....love from Kenya.
Very impressive, agreed. A friend of mine knows the date trick, but it takes him about a minute to tell you what day it is, whereas this guy will tell you in a few seconds. :)