ABOUT THE SPEAKER
Arthur Benjamin - Mathemagician
Using daring displays of algorithmic trickery, lightning calculator and number wizard Arthur Benjamin mesmerizes audiences with mathematical mystery and beauty.

Why you should listen

Arthur Benjamin makes numbers dance. In his day job, he's a professor of math at Harvey Mudd College; in his other day job, he's a "Mathemagician," taking the stage in his tuxedo to perform high-speed mental calculations, memorizations and other astounding math stunts. It's part of his drive to teach math and mental agility in interesting ways, following in the footsteps of such heroes as Martin Gardner.

Benjamin is the co-author, with Michael Shermer, of Secrets of Mental Math (which shares his secrets for rapid mental calculation), as well as the co-author of the MAA award-winning Proofs That Really Count: The Art of Combinatorial Proof. For a glimpse of his broad approach to math, see the list of research talks on his website, which seesaws between high-level math (such as his "Vandermonde's Determinant and Fibonacci SAWs," presented at MIT in 2004) and engaging math talks for the rest of us ("An Amazing Mathematical Card Trick").

More profile about the speaker
Arthur Benjamin | Speaker | TED.com
TED2005

Arthur Benjamin: A performance of "Mathemagic"

"Matemagija" Arthurja Benjamina

Filmed:
9,599,588 views

Matematik Arthur Benjamin tokrat poskuša premagati kalkulatorje pri kvadriranju, uganjuje rojstne dneve in reši ogromno miselno uganko. Kako mu vse to uspe? Povedal vam bo.
- Mathemagician
Using daring displays of algorithmic trickery, lightning calculator and number wizard Arthur Benjamin mesmerizes audiences with mathematical mystery and beauty. Full bio

Double-click the English transcript below to play the video.

00:13
Well, good morningjutro ladiesgospe and gentlemengospodje.
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Pozdravljeni, dame in gospodje.
00:14
My nameime is ArtArt BenjaminBenjamin, and I am a "mathemagicianMathemagician."
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Ime mi je Art Benjamin in sem "matematični čarovnik".
00:18
What that meanssredstva is, I combinezdružiti my lovesljubi of mathmatematika and magicmagija
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To pomeni, da združujem svojo ljubezen do matematike in magije,
00:21
to do something I call "mathemagicsmathemagics."
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da ustvarim tako imenovano "matemagijo".
00:24
But before I get startedzačel, I have a quickhitro questionvprašanje for the audienceobčinstvo.
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A preden začnem, imam kratko vprašanje za vas.
00:27
By any chancepriložnost, did anyonekdorkoli happense zgodi
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Ima slučajno kdo
00:29
to bringprinesi with them this morningjutro a calculatorkalkulator?
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s sabo kalkulator?
00:33
SeriouslyResno, if you have a calculatorkalkulator with you, raisedvigni your handroka, raisedvigni your handroka.
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Resno mislim, če imate kalkulator, dvignite roko.
00:37
I -- was -- your handroka go up?
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Torej, ste dvignili roko?
00:39
Now bringprinesi it out, bringprinesi it out. AnybodyVsakdo elsedrugače?
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Kar dvignite jih. Še kdo?
00:41
I see, I see one way in the back.
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Vidim eno tam zadaj.
00:43
You sirGospod, that's threetri,
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Vi gospod, torej 3 roke.
00:45
And anybodykdorkoli on this sidestran here?
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Še kdo na tej strani?
00:48
OK, you over there on the aisleoltarja. Would the fourštiri of you with calculatorskalkulatorji
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OK, še vi tam ob strani. Lahko vi s kalkulatorji
00:50
please bringprinesi out your calculatorskalkulatorji, then joinPridružite se me up on stagestopnja.
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pridete sedaj na oder?
00:53
And let's give these volunteersprostovoljci a nicelepo roundokrogla of applauseaplavz.
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Zaploskajmo našim prostovoljcem.
00:55
(ApplauseAplavz)
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(Aplavz)
00:58
That's right. Now, sinceod I haven'tne had the chancepriložnost
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Torej, ker nisem še nikoli delal
01:01
to work with these calculatorskalkulatorji, I need to make sure
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s temi kalkulalatorji, se moram prepričati,
01:04
that they are all workingdelo properlypravilno.
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da vsi pravilno delujejo.
01:06
Would somebodynekdo get us startedzačel by givingdajanje us a
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Lahko kdo začne
01:08
two-digitdvomestno numberštevilka please?
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z dvoštevilčno številko?
01:11
How about a two-digitdvomestno numberštevilka?
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Torej eno dvomestno prosim?
01:13
AudienceObčinstvo: 22.
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22.
01:14
ArthurArthur BenjaminBenjamin: 22. And anotherdrugo two-digitdvomestno numberštevilka, SirGospod?
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V redu, še kakšna?
01:16
AudienceObčinstvo: 47.
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47.
01:17
ABAB: MultiplyPomnožite 22 timeskrat 47, make sure you get 1,034,
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Zmnožite 22 s 47, dobili boste 1034,
01:21
or the calculatorskalkulatorji are not workingdelo. Do all of you get 1,034? 1,034?
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razen seveda če kalkulatorji ne delajo. Ste vsi dobili 1034?
01:26
WomanŽenska: No.
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Ne.
01:27
ABAB: 594. Let's give threetri of them a nicelepo roundokrogla of applauseaplavz there.
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594. No vseeno jim zaploskajmo.
01:31
(ApplauseAplavz)
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(Aplavz)
01:33
Would you like to try a more standardstandard calculatorkalkulator, just in caseprimera?
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Bi raje poskusili z bolj preprostim kalkulatorjem?
01:35
OK, great.
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OK, super.
01:37
What I'm going to try and do then --
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Poskusil bom torej...
01:39
I noticeopaziti that tookvzel some of you a little bitbit of time to get your answerodgovor.
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...opažam, da ste potrebovali kar nekaj časa za računanje.
01:42
That's OK. I'll give you a shortcutbližnjico for multiplyingmnoženje
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Dal vam bom bližnjico za še hitrejše
01:45
even fasterhitreje on the calculatorkalkulator.
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množenje s kalkulatorjem.
01:47
There is something calledpozval the squarekvadrat of a numberštevilka,
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Obstaja nekaj, čemur pravimo kvadrat števila,
01:49
whichki mostnajbolj of you know is takingjemanje a numberštevilka
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kot veste ga dobimo z množenjem
01:51
and multiplyingmnoženje it by itselfsama.
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števila samega s seboj.
01:53
For instanceprimer, fivepet squaredkvadrat would be?
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Torej, kvadrat od 5 bi bil?
01:55
AudienceObčinstvo: 25.
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25.
01:56
ABAB: 25. Now, the way we can squarekvadrat on mostnajbolj calculatorskalkulatorji --
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25. Torej, kako lahko kvadriramo na kalkulatorju --
01:58
let me demonstratedokazati with this one --
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bom pokazal na tem --
02:00
is by takingjemanje the numberštevilka, suchtako as fivepet,
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vzamemo število, kot je 5
02:02
hittingudaril "timeskrat" and then "equalsenako,"
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pritisnemo gumb "krat", nato "je enako".
02:05
and on mostnajbolj calculatorskalkulatorji that will give you the squarekvadrat.
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Večina kalkulatorjev bo tako pokazala kvadrat.
02:08
On some of these ancientstarodavne RPNOBRNJENI POLJSKI ZAPIS calculatorskalkulatorji,
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Na nekaterih starinskih kalkulatorjih,
02:10
you've got an "x squaredkvadrat" buttongumb on it,
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imate gumb "x na kvadrat",
02:12
will allowdovolite you to do the calculationizračun even fasterhitreje.
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kar vam še pospeši računanje.
02:15
What I'm going to try and do now is to squarekvadrat, in my headglava,
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Sedaj bom poskušal na pamet kvadrirati
02:18
fourštiri two-digitdvomestno numbersštevilke
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štiri dvomestna števila,
02:20
fasterhitreje than they can do on theirnjihovi calculatorskalkulatorji, even usinguporabo the shortcutbližnjico methodmetoda.
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hitreje kakor oni s kalkulatorji, tudi če si bodo pomagali z bližnjicami.
02:24
What I'll use is the seconddrugič rowvrstico this time, and I'll get fourštiri of you --
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Sedaj bom izbral drugo vrsto in poiskal 4 gledalce,
02:26
one, two, threetri, fourštiri -- to eachvsak yellvikati out a two-digitdvomestno numberštevilka,
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da vsak od njih pove eno dvomestno število.
02:29
and if you would squarekvadrat the first numberštevilka,
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Vi pa boste kvadrirali prvo število,
02:33
and if you would squarekvadrat the seconddrugič, the thirdtretjino and the fourthčetrti,
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vi drugo, tretje in vi četrto.
02:35
I will try and racedirka you to the answerodgovor. OK?
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Jaz pa vas bom poskušal prehiteti. V redu?
02:38
So quicklyhitro, a two-digitdvomestno numberštevilka please.
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Torej hitro -- dvomestno število prosim?
02:41
AudienceObčinstvo: 37.
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37.
02:42
ABAB: 37 squaredkvadrat, OK.
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37 na kvadrat, OK.
02:44
AudienceObčinstvo: 23.
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23.
02:45
ABAB: 23 squaredkvadrat, OK.
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23 na kvadrat, OK.
02:47
AudienceObčinstvo: 59.
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59.
02:48
ABAB: 59 squaredkvadrat, OK, and finallykončno?
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59 na kvadrat, in še?
02:49
AudienceObčinstvo: 93.
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93.
02:51
ABAB: 93 squaredkvadrat. Would you call out your answersodgovore, please?
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93 na kvadrat. Bi lahko povedali rezultate prosim?
02:54
WomanŽenska: 1369. ABAB: 1369.
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1369. - 1369
02:56
WomanŽenska: 529.
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529.
02:57
ABAB: 529.
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529
02:58
Man: 3481.
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3481
02:59
ABAB: 3481.
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3481
03:00
Man: 8649.
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8649
03:01
ABAB: Thank you very much.
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Najlepša hvala.
03:02
(ApplauseAplavz)
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(Aplavz)
03:07
Let me try to take this one stepkorak furthernadalje.
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Pa pojdimo še en korak naprej.
03:10
I'm going to try to squarekvadrat some three-digittri-mestno numbersštevilke this time.
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Sedaj bom kvadriral trimestna števila.
03:13
I won'tne bo even writepiši these down --
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Sploh jih ne bom zapisal --
03:15
I'll just call them out as they're calledpozval out to me.
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jih bom pač le izgovoril.
03:17
AnyoneKdorkoli I pointtočka to, call out a three-digittri-mestno numberštevilka.
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Mi lahko kdo pove eno trimestno število?
03:20
AnyoneKdorkoli on our panelpanel, verifypreveri the answerodgovor.
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Nekdo tukaj pa naj preveri odgovor.
03:22
Just give some indicationindikacija if it's right.
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Samo dajte mi znak, če je pravilen.
03:24
A three-digittri-mestno numberštevilka, sirGospod, yes?
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Trimestno število torej?
03:27
AudienceObčinstvo: 987.
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987.
03:28
ABAB: 987 squaredkvadrat is 974,169.
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987 na kvadrat je 974,169.
03:31
(LaughterSmeh)
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(Smeh)
03:33
Yes? Good.
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Je? Super.
03:35
AnotherDrugo, anotherdrugo three-digittri-mestno --
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Še kakšno število?
03:37
(ApplauseAplavz)
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(Aplavz)
03:38
-- anotherdrugo three-digittri-mestno numberštevilka, sirGospod?
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Še kakšno trimestno prosim?
03:41
AudienceObčinstvo: 457.
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457.
03:42
ABAB: 457 squaredkvadrat is 205,849.
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457 na kvadrat je 205,849.
03:45
205,849?
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205,849?
03:47
Yes?
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Je?
03:49
OK, anotherdrugo, anotherdrugo three-digittri-mestno numberštevilka, sirGospod?
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OK, še eno prosim?
03:52
AudienceObčinstvo: 321.
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321.
03:53
ABAB: 321 is 103,041. 103,041.
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321 je 103,041. 103,041.
03:56
Yes? One more three-digittri-mestno numberštevilka please.
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Ja, še eno?
03:59
AudienceObčinstvo: Oh, 722.
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722.
04:01
ABAB: 722 is 500 -- oohOoh, that's a hardertežje one.
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722 je pa 500 ... uf ta je pa težka.
04:04
Is that 513,284?
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Je mogoče 513,284?
04:07
WomanŽenska: Yes.
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Je.
04:08
ABAB: Yes? Oh, one more, one more three-digittri-mestno numberštevilka please.
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Ja? OK še eno trimestno prosim?
04:11
AudienceObčinstvo: 162.
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Občinstvo: 162.
04:12
162 squaredkvadrat is 26,244.
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162 na kvadrat je 26,244.
04:16
Thank you very much.
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Najlepša hvala.
04:18
(ApplauseAplavz)
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(Aplavz)
04:25
Let me try to take this one stepkorak furthernadalje.
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No pa poskusimo iti še en korak naprej.
04:28
(LaughterSmeh)
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(Smeh)
04:30
I'm going to try to squarekvadrat a four-digitštiri-mestno numberštevilka this time.
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Kvadriral bom štirimestno število.
04:33
Now you can all take your time on this; I will not beatpremagati you to the answerodgovor on this one,
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Tukaj ne bom hitrejši od vas,
04:36
but I will try to get the answerodgovor right.
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vendar bom pa poskusil pravilno odgovoriti.
04:38
To make this a little bitbit more randomnaključen, let's take the fourthčetrti rowvrstico this time,
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Pa vzemimo tokrat četrto vrsto, da bo bolj naključno,
04:41
let's say, one, two, threetri, fourštiri.
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recimo, prvi, drugi, tretji, četrti.
04:44
If eachvsak of you would call out a singlesamski digitmestno betweenmed zeronič and ninedevet,
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Če lahko vsak prosim pove eno enomestno številko,
04:46
that will be the four-digitštiri-mestno numberštevilka that I'll squarekvadrat.
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tako da bomo dobili štiri števke, ki jih bom kvadriral.
04:49
AudienceObčinstvo: NineDevet.
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9.
04:50
ABAB: NineDevet.
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9.
04:51
AudienceObčinstvo: SevenSedem. ABAB: SevenSedem.
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7.
04:52
AudienceObčinstvo: FivePet. ABAB: FivePet.
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5
04:53
AudienceObčinstvo: EightOsem. ABAB: EightOsem.
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8.
04:55
9,758, this will take me a little bitbit of time, so bearmedveda with me.
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Torej 9758, tukaj potrebujem nekaj časa, prosim počakajte.
04:58
95,218,564?
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Je 95,218,564?
05:07
WomanŽenska: Yes.
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Ja.
05:08
ABAB: Thank you very much.
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Najlepša hvala.
05:10
(ApplauseAplavz)
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(Aplavz)
05:18
Now, I would attemptposkus to squarekvadrat a five-digitpet-mestno numberštevilka --
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Sedaj pa bom kvadriral petmestno število --
05:21
and I can --
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in jaz to lahko --
05:23
but unfortunatelyna žalost mostnajbolj calculatorskalkulatorji cannotne morem.
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a večina kalkulatorjev tega ne zmore.
05:25
(LaughterSmeh)
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(Smeh)
05:27
Eight-digit8-mestno capacityzmogljivost -- don't you hatesovraštvo that?
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Osemštevilčna kapaciteta -- gotovo jo sovražite.
05:30
So, sinceod we'vesmo reacheddosegel the limitsomejitve of our calculatorskalkulatorji --
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Torej, ker smo dosegli limit kalkulatorjev...
05:33
what's that? Does yourstvoja go --
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Kaj pravite? Gre vaš --
05:36
WomanŽenska: I don't know.
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Ne vem.
05:37
ABAB: Does yourstvoja go highervišje?
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Gre vaš še višje?
05:39
Oh -- yourstvoja does?
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O, vaš gre?
05:41
Man: I can probablyverjetno do it.
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Gospod: Jaz bi verjetno zmogel.
05:42
ABAB: I'll talk to you laterpozneje.
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Se pogovoriva kasneje.
05:44
In the meanwhilemedtem, let me concludezaključiti
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Medtem pa naj zaključim
05:46
the first partdel of my showshow by doing something a little trickierTežavnejša.
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prvi del predstave z nečim še malo težjim.
05:49
Let's take the largestnajvečji numberštevilka on the boardtabla here, 8649.
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Vzemimo največje število tukaj, torej 8649.
05:52
Would you eachvsak entervnesite that on your calculatorkalkulator?
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Jo lahko vpišete v kalkulator?
05:55
And insteadnamesto tega of squaringKvadratura it this time,
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In namesto, da bi jo kvadrirali,
05:57
I want you to take that numberštevilka and multiplypomnoži it
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jo pomnožite s katerokoli trimestno
05:59
by any three-digittri-mestno numberštevilka that you want,
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številko, ki vam pride na misel.
06:02
but don't tell me what you're multiplyingmnoženje by --
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Ampak ne povejte mi, s katero ste množili --
06:04
just multiplypomnoži it by any randomnaključen three-digittri-mestno numberštevilka.
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samo zmnožite z naključno trimestno številko.
06:07
So you should have as an answerodgovor eitherbodisi
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Torej rezultat bo ali šestmestna
06:09
a six-digit6-mestno or probablyverjetno a seven-digitsedem-mestno numberštevilka.
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ali najbrž sedemmestna številka.
06:13
How manyveliko digitsštevk do you have, sixšest or sevensedem?
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Koliko mest ima vaša, šest ali sedem?
06:14
SevenSedem, and yourstvoja? WomanŽenska: SevenSedem.
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Sedem, vaša? Sedem.
06:16
ABAB: SevenSedem? SevenSedem?
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Sedem? Sedem?
06:19
And, uncertainnegotovo.
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Aha, vi pa na veste.
06:21
Man: Yeah.
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Gospod: Ja.
06:22
ABAB: SevenSedem. Is there any possiblemogoče way that I could know
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Sedem. Obstaja kakšen način, kako bom vedel,
06:24
what sevensedem digitmestno numbersštevilke you have? Say "No."
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katero sedemmestno število ste dobili. Recite "ne".
06:27
(LaughterSmeh)
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(Smeh)
06:29
Good. Then I shallse attemptposkus the impossiblenemogoče --
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Dobro, torej bom poskusil nemogoče --
06:31
or at leastvsaj the improbableneverjeten.
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oziroma vsaj neverjetno.
06:33
What I'd like eachvsak of you to do is to call out for me
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Povejte mi katerihkoli šest števk izmed
06:35
any sixšest of your sevensedem digitsštevk, any sixšest of them,
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vaših sedmih števk, v kakršnemkoli
06:38
in any orderred you'dTi bi like.
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vrstnem redu.
06:40
(LaughterSmeh)
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(Smeh)
06:41
One digitmestno at a time, I shallse try and determinedoločiti the digitmestno you've left out.
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In jaz bom poskusil ugotoviti, katero števko ste izpustili.
06:46
So, startingzačetek with your seven-digitsedem-mestno numberštevilka,
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Torej začnimo z vašim številom.
06:48
call out any sixšest of them please.
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Povejte katerihkoli šest.
06:50
WomanŽenska: One, OK, 197042.
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Torej, 197042.
06:56
ABAB: Did you leavedopust out the numberštevilka 6?
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Ste izpustili 6?
06:57
WomanŽenska: Yes, ABAB: Good, OK, that's one.
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Gospa: Ja. Art: Dobro.
06:59
You have a seven-digitsedem-mestno numberštevilka, call out any sixšest of them please.
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Vaša sedemmestnica, povejte šest števk.
07:01
WomanŽenska: 44875.
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44875.
07:04
ABAB: I think I only heardslišal fivepet numbersštevilke. I -- wait -- 44875 --
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Art: Slišal sem le pet števk. Am -- čakajte -- 44875...
07:09
did you leavedopust out the numberštevilka 6?
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Ste izpustili številko 6?
07:11
WomanŽenska: Yes. ABAB: SameIsti as she did, OK. You've got a seven-digitsedem-mestno numberštevilka --
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Gospa: Ja. Art: Torej enako kot ona, OK. Še vaša sedemmestna --
07:13
call out any sixšest of them loudglasno and clearjasno.
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povejte mi šest števk.
07:16
Man: 079044.
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079044.
07:20
ABAB: I think you left out the numberštevilka 3?
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Mislim da ste izpustili 3?
07:22
That's threetri. The oddskvote of me gettingpridobivanje all fourštiri of these right by randomnaključen guessingugibati
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Torej imamo že tri. Možnost, da bi vse tole naključno uganil, je
07:26
would be one in 10,000: 10 to the fourthčetrti powermoč.
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1 proti 10,000. Torej 10 na četrto.
07:29
OK, any sixšest of them.
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OK, šest števk prosim.
07:32
Really scrambleIzokrenuti them up this time, please.
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Pa res jih premešajte, prosim.
07:34
Man: 263972.
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263972.
07:38
ABAB: Did you leavedopust out the numberštevilka 7?
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Ste izpustili 7?
07:40
And let's give all fourštiri of these people a nicelepo roundokrogla of applauseaplavz.
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Zaploskajmo vsem štirim prostovoljcem.
07:42
Thank you very much. (ApplauseAplavz)
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Najlepša hvala.
07:52
For my nextNaslednji numberštevilka --
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Za naslednjo številko --
07:54
(LaughterSmeh)
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(Smeh)
07:57
while I mentallyduševno rechargepolnjenje my batteriesbaterije,
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medtem ko si odahnem možgane,
07:59
I have one more questionvprašanje for the audienceobčinstvo.
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imam še eno vprašanje za občinstvo.
08:02
By any chancepriložnost, does anybodykdorkoli here happense zgodi to know
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Slučajno kdo ve, na kateri dan
08:07
the day of the weekteden that they were bornRojen on?
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v tednu se je rodil?
08:10
If you think you know your birthrojstvo day, raisedvigni your handroka.
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Če že veste, dvignite roko.
08:14
Let's see, startingzačetek with -- let's startZačni with a gentlemangospod first,
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No pa poglejmo, vi gospod
08:17
OK sirGospod, what yearleto was it, first of all? That's why I startZačni with a gentlemangospod first.
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OK, letnico prosim? Zato seveda začenjam z gospodom.
08:20
What yearleto?
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Katerega leta?
08:21
AudienceObčinstvo: 1953.
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1953.
08:22
ABAB: 1953, and the monthmesec?
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1953. Mesec?
08:24
AudienceObčinstvo: NovemberNovembra. ABAB: NovemberNovembra what?
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November. - Kateri november?
08:25
AudienceObčinstvo: 23rdRD.
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23.
08:26
ABAB: 23rdRD -- was that a MondayPonedeljek? AudienceObčinstvo: Yes.
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23. november -- ponedeljek? - Ja.
08:28
Yes, good. SomebodyNekdo elsedrugače? Who elsedrugače would like --
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Aha, dobro. Še kdo?
08:30
see I don't -- haven'tne seenvidel any women'sženske handsroke up.
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Ne vidim nobenih ženskih rok.
08:32
OK, it's -- how about you, what yearleto?
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OK tukaj imamo -- katerega leta?
08:34
AudienceObčinstvo: 1949. ABAB: 1949, and the monthmesec?
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1949. - In mesec?
08:36
AudienceObčinstvo: OctoberOktobra. ABAB: OctoberOktobra what?
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Oktober. - Kateri oktober?
08:37
AudienceObčinstvo: FifthPeti.
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Peti.
08:38
ABAB: FifthPeti -- was that a WednesdaySreda?
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5. oktober -- je bila sreda?
08:40
Yes, my -- I'll go way to the back right now, how about you?
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Aha, grem še malo tja zadaj, kaj pa vi?
08:42
YellKričati it out, what yearleto? AudienceObčinstvo: 1959.
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Katerega leta? - 1959.
08:44
ABAB: 1959, OK -- and the monthmesec?
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OK, še mesec?
08:46
AudienceObčinstvo: FebruaryFebruarja.
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Februar.
08:48
ABAB: FebruaryFebruarja what? AudienceObčinstvo: SixthŠesti.
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Kateri februar? - Šesti.
08:50
ABAB: SixthŠesti -- was that a FridayPetek? AudienceObčinstvo: Yes.
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Šesti -- je bil mogoče petek? - Ja.
08:52
Good, how about the personoseba behindzadaj her?
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Dobro, kaj pa gospa zadaj?
08:54
Call -- call -- what yearleto was it?
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Katerega leta?
08:56
AudienceObčinstvo: 1947. ABAB: 1947, and the monthmesec?
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1947. - Mesec?
08:58
AudienceObčinstvo: MayMaja. ABAB: MayMaja what?
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Maj. - Kateri maj?
09:00
AudienceObčinstvo: SeventhSedmi. ABAB: SeventhSedmi -- would that be a WednesdaySreda?
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Sedmi. - Sedmi maj -- sreda kajne?
09:02
AudienceObčinstvo: Yes.
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Ja.
09:03
ABAB: Thank you very much.
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Najlepša hvala.
09:05
(ApplauseAplavz)
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(Aplavz)
09:09
AnybodyVsakdo here who'dkdo bi like to know the day of the weekteden they were bornRojen?
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Bi kdo rad izvedel, katerega dne v tednu se je rodil?
09:12
We can do it that way.
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Lahko se gremo tudi tako.
09:14
Of courseseveda, I could just make up an answerodgovor and you wouldn'tne bi know,
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Seveda, lahko bi si samo izmislil odgovor, saj ne bi nihče vedel.
09:16
so I come preparedpripravljen for that.
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A prišel sem pripravljen.
09:18
I broughtprinesel with me a bookknjigo of calendarskoledarji.
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S sabo imam koledarje,
09:21
It goesgre as fardaleč back into the pastpreteklost as 1800, 'causeker you never know.
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ki segajo do leta 1800. Nikoli ne veš.
09:25
(LaughterSmeh)
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(Smeh)
09:27
I didn't mean to look at you, sirGospod --
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Nisem gledal vas, gospod,
09:29
you were just sittingsedi there.
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samo tam pač sedite.
09:31
AnywayKakorkoli že, ChrisChris, you can help me out here, if you wouldn'tne bi mindum.
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Kakorkoli že, Chris, če mi lahko prosim pomagaš.
09:34
This is a bookknjigo of calendarskoledarji, and I'll askvprašajte --
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To je knjiga koledarjev, torej
09:36
who was it that wanted to know theirnjihovi birthrojstvo day? You sirGospod? OK.
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kdo je hotel izvedeti, na kateri dan v tednu se je rodil? Vi gospod? OK.
09:38
What yearleto was it, first of all?
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Torej, najprej, katerega leta?
09:40
AudienceObčinstvo: 1966.
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1966.
09:41
ABAB: '66 -- turnobrat to the calendarkoledar with 1966 --
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1966 -- obrni koledar na 1966,
09:43
and what monthmesec?
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še mesec?
09:45
AudienceObčinstvo: AprilAprila. ABAB: AprilAprila what?
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April. - Kateri april?
09:47
AudienceObčinstvo: 17thth. ABAB: 17thth -- I believe that was a SundayNedelja.
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17. - To bo pa nedelja.
09:50
Can you confirmpotrdite, ChrisChris?
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Se strinjaš, Chris?
09:52
ChrisChris AndersonAnderson: Yes. ABAB: Yeah, OK. I'll tell you what, ChrisChris:
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Ja. - OK, poglej Chris.
09:54
as long as you have that bookknjigo in frontspredaj of you,
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Če že imaš to knjigo,
09:57
do me a favoruslugo, turnobrat to a yearleto outsidezunaj of the 1900s,
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prosim, obrni jo nekam globoko v 19. stoletje,
10:01
eitherbodisi into the 1800s or way into the 2000s --
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ali pa v 21. stoletje --
10:04
that'llto bo be a much greatervečje challengeizziv for me.
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to bo veliko večji izziv.
10:06
What yearleto, ChrisChris, would you like?
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Katero leto, Chris?
10:07
CACA: 1824.
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1824.
10:08
ABAB: 1824, OK.
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OK.
10:11
And what monthmesec? CACA: JuneJunija.
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Še mesec? - Junij.
10:13
ABAB: JuneJunija what? CACA: SixthŠesti.
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Kateri junij? - Šesti.
10:15
ABAB: SixthŠesti -- was that a SundayNedelja?
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Šesti -- je bila nedelja?
10:17
CACA: It was. ABAB: And it was cloudyoblačno.
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Je. - In bilo je oblačno.
10:20
Good, thank you very much.
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Najlepša hvala.
10:22
(ApplauseAplavz)
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(Aplavz)
10:28
But I'd like to wrapzaviti things up now
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Zdaj pa bi rad počasi zaključil
10:30
by alludingnamigoval to something
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z namigom na nekaj
10:33
from earlierprej in the presentationpredstavitev.
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z začetka predstave.
10:35
There was a gentlemangospod up here who had a 10-digit-mestno calculatorkalkulator.
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Imeli smo možakarja z desetmestnim kalkulatorjem.
10:38
Where is he, would you standstojalo up,
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Kje je, lahko vstane?
10:42
10-digit-mestno guy?
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Desetmestnik?
10:44
OK, well standstojalo up for me just for a seconddrugič,
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OK, vstanite za trenutek,
10:47
so I can see where you are.
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da vidim, kje ste.
10:49
OK, oh, OK -- you have a 10-digit-mestno calculatorkalkulator, sirGospod, as well?
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OK -- imate vi tudi desetmestni kalkulator?
10:52
OK, what I'm going to try and do, is to squarekvadrat in my headglava
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OK, na pamet bom poskusil kvadrirati
10:56
a five-digitpet-mestno numberštevilka requiringki zahtevajo a 10-digit-mestno calculatorkalkulator.
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petmestno številko, kar zahteva desetmestni kalkulator.
10:59
But to make my jobdelo more interestingzanimivo for you, as well as for me,
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A da bo moje delo bolj zanimivo,
11:04
I'm going to do this problemproblem
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bom tokrat
11:06
thinkingrazmišljanje out loudglasno.
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razmišljal naglas.
11:08
So you can actuallydejansko, honestlyiskreno hearslišite
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Tako, da boste slišali,
11:11
what's going on in my mindum
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kaj se dejansko dogaja v moji glavi,
11:13
while I do a calculationizračun of this sizevelikost.
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ko računam s takimi številkami.
11:15
Now, I have to apologizese opravičujem to our magicianČarovnik friendprijatelj LennartLennart GreenZelena.
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Najprej se moram opravičiti čarovniku Lennartu Greenu.
11:18
I know as a magicianČarovnik we're not supposeddomnevno to revealrazkrivajo our secretsskrivnosti,
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Vem, da kot čarovnik ne bi smel razkriti takih skrivnosti,
11:22
but I'm not too afraidstrah that people are going
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a mislim, da me ljudje še ne bodo uspeli
11:24
to startZačni doing my showshow nextNaslednji weekteden, so --
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posnemati naslednji teden.
11:26
I think we're OK.
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Mislim da smo varni.
11:30
So, let's see, let's take a --
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No, da vidimo,
11:33
let's take a differentdrugačen rowvrstico of people, startingzačetek with you.
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vzemimo še eno drugo vrsto ljudi, začnimo tu.
11:35
I'll get fivepet digitsštevk: one, two, threetri, fourštiri --
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Dobiti moram pet števk: ena, dva, tri, štiri --
11:38
oh, I did this rowvrstico alreadyže. Let's do the rowvrstico before you,
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o, saj to vrsto sem že obdelal. Poglejmo raje to pred vami,
11:40
startingzačetek with you sirGospod: one, two, threetri, fourštiri, fivepet.
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vi gospod,: ena, dva, tri, štiri, pet.
11:43
Call out a singlesamski digitmestno -- that will be the five-digitpet-mestno numberštevilka
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Povejte po eno števko -- tako da bomo dobili petmestno
11:46
that I will try to squarekvadrat. Go aheadnaprej.
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številko, ki jo bom kvadriral.
11:48
AudienceObčinstvo: FivePet. ABAB: FivePet.
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Pet. - Pet.
11:50
AudienceObčinstvo: SevenSedem. ABAB: SevenSedem.
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Sedem. - Sedem.
11:51
AudienceObčinstvo: SixŠest. ABAB: SixŠest.
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Šest. - Šest.
11:52
AudienceObčinstvo: EightOsem. ABAB: EightOsem.
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Osem. - Osem.
11:54
AudienceObčinstvo: ThreeTri. ABAB: ThreeTri.
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Tri. - Tri.
11:56
57,683
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57,683
12:01
squaredkvadrat. YuckFuj.
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kvadriramo. Ojoj.
12:03
Let me explainpojasnite to you how
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Naj vam razložim,
12:05
I'm going to attemptposkus this problemproblem.
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kako se bom lotil.
12:08
I'm going to breakodmor the problemproblem down into threetri partsdeli.
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Problem razčlenim na tri dele.
12:11
I'll do 57,000 squaredkvadrat,
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Torej, kvadriram 57,000
12:13
plusplus 683 squaredkvadrat,
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temu prištejem kvadrat od 683.
12:17
plusplus 57,000 timeskrat
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Prištejem 57,000 krat
12:20
683 timeskrat two.
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683 krat dve.
12:22
AddDodaj all those numbersštevilke togetherskupaj,
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Ko seštejemo vse to,
12:24
and with any luckSreča, arriveprispejo at the answerodgovor.
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z nekaj sreče dobimo odgovor.
12:28
Now, let me recapRekapitulacija.
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Torej, naj povzamem.
12:31
Thank you.
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Hvala.
12:34
While I explainpojasnite something elsedrugače --
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Medtem pa naj še nekaj pojasnim --
12:37
-- I know, that you can use, right?
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nekaj, kar vam bo prišlo prav.
12:40
While I do these calculationizračun[s],
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Medtem, ko to računam,
12:42
you mightmorda hearslišite certainnekateri wordsbesede,
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boste mogoče slišali nekaj besed
12:44
as opposednasprotuje to numbersštevilke, creeplezenje into the calculationizračun.
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namesto številk v mojih računih.
12:48
Let me explainpojasnite what that is.
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Naj pojasnim.
12:49
This is a phoneticfonetične codeKoda,
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To je glasovna koda,
12:51
a mnemonicokrajšava devicenaprave that I use,
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mnemotehnika, ki jo uporabljam,
12:53
that allowsdovoljuje me to convertpretvoriti numbersštevilke into wordsbesede.
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ki omogoča, da pretvorim številke v besede.
12:56
I storeshranite them as wordsbesede, and laterpozneje on retrievepridobiti them as numbersštevilke.
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Zapomnim si jih kot besede, kasneje pa jih prikličem
12:59
I know it soundszvoki complicatedzapleteno; it's not --
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kot številke. Sliši se zapleteno, a ni.
13:01
I just don't want you to think you're seeingvidenje something out of "RainDež Man" here.
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A nočem, da mislite, da sem Rain Man.
13:04
(LaughterSmeh)
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(Smeh)
13:06
There's definitelydefinitivno a methodmetoda to my madnessnorost --
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Zagotovo ima ta norost nek smisel --
13:08
definitelydefinitivno, definitelydefinitivno. Sorry.
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zagotovo, zagotovo. Oprostite.
13:10
(LaughterSmeh)
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(Smeh)
13:14
If you want to talk to me about ADHDADHD afterwardspotem,
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Če bi se radi pogovorili o hiperaktivnosti,
13:16
you can talk to me then. All right --
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me poiščite kasneje. Torej --
13:18
by the way, one last instructionnavodila,
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mimogrede, še zadnje navodilo
13:20
for my judgessodniki with the calculatorskalkulatorji -- OK, you know who you are --
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za moje sodnike s kalkulatorji -- saj veste, kdo ste.
13:23
there is at leastvsaj a 50 percentodstotkov chancepriložnost
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Obstaja najmanj 50% možnosti,
13:26
that I will make a mistakenapaka here.
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da se bom zmotil.
13:29
If I do, don't tell me what the mistakenapaka is;
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Če se, mi ne povejte, kje je napaka.
13:32
just say, "you're closeblizu," or something like that, and I'll try and figureštevilka out the answerodgovor --
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Samo recite, da "sem blizu" ali kaj takega, pa bom že našel rešitev --
13:35
whichki could be prettylepa entertainingzabavno in itselfsama.
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kar bo najbrž precej zabavno.
13:39
If, howeverVendar, I am right,
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Če pa se ne bom zmotil,
13:41
whateverkarkoli you do, don't keep it to yourselfsami, OK?
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mi to povejte, ne držite tega zase. OK?
13:44
(LaughterSmeh)
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(Smeh)
13:45
Make sure everybodyvsi knowsve that I got the answerodgovor right,
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Vsi morajo vedeti, da sem pravilno izračunal,
13:47
because this is my bigvelik finishkonča, OK.
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saj bo to moj veliki zaključek, OK.
13:50
So, withoutbrez any more stallinghlev,
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Torej, brez zavlačevanja,
13:53
here we go.
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pa pojdimo.
13:56
I'll startZačni the problemproblem in the middlesredi, with 57 timeskrat 683.
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Začnimo kar na sredini. 57 krat 683.
13:58
Now, 57 timeskrat 68 is 3,400, plusplus 476 is 3876,
334
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57 krat 68 je 3,400, plus 476 je 3876,
14:01
that's 38,760 plusplus 171,
335
829000
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to je 38,760 plus 171.
14:04
38,760 plusplus 171 is 38,931.
336
832000
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To je 38,931.
14:07
38,931; doubledvojno that to get 77,862.
337
835000
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Podvojimo in dobimo 77,862.
14:11
77,862 becomespostane cookiepiškotek fissioncepitve,
338
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77,862 postane fizija piškotov,
14:13
cookiepiškotek fissioncepitve is 77,822.
339
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fizija piškotov je 77,822.
14:17
That seemsZdi se right, I'll go on. CookiePiškotek fissioncepitve, OK.
340
845000
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To se sliši v redu, gremo naprej. OK.
14:19
NextNaslednji, I do 57 squaredkvadrat, whichki is 3,249, so I can say,
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Sedaj pa kvadrirajmo 57, to je 3,249. Torej,
14:23
threetri billionmilijardo. Take the 249, adddodaj that to cookiepiškotek, 249,
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to so tri milijarde. Vzamemo 249, dodamo to piškotom.
14:28
oopsups, but I see a carrynositi comingprihajajo --
343
856000
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Opa, ovira je na vidiku --
14:30
249 --
344
858000
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249 --
14:32
adddodaj that to cookiepiškotek, 250 plusplus 77,
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plus piškoti, 250 plus 77
14:34
is 327 millionmilijonov --
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je 327 milijonov.
14:38
fissioncepitve, fissioncepitve, OK, finallykončno, we do 683 squaredkvadrat,
347
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Fizija, fizija. OK, kvadriramo še 683,
14:41
that's 700 timeskrat 666, plusplus 17 squaredkvadrat
348
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to je 700 krat 666 plus 17 na kvadrat
14:43
is 466,489, revRev up if I need it,
349
871000
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to je 466,489,
14:46
revRev up, take the 466,
350
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vzamemo še to,
14:48
adddodaj that to fissioncepitve, to get,
351
876000
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dodamo fiziji, da dobimo
14:50
oh geeJoj --
352
878000
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ojoj --
14:54
328,489.
353
882000
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328,489.
14:58
AudienceObčinstvo: Yeah!
354
886000
1000
Ja!
14:59
ABAB: Good.
355
887000
1000
Dobro.
15:00
(ApplauseAplavz)
356
888000
1000
(Aplavz)
15:01
Thank you very much.
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Najlepša hvala.
15:03
I hopeupanje you enjoyeduživali mathemagicsmathemagics. Thank you.
358
891000
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Upam, da ste uživali v matemagiji. Hvala.
15:05
(ApplauseAplavz)
359
893000
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(Aplavz)
Translated by Nace Zavrl
Reviewed by Klavdija Cernilogar

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ABOUT THE SPEAKER
Arthur Benjamin - Mathemagician
Using daring displays of algorithmic trickery, lightning calculator and number wizard Arthur Benjamin mesmerizes audiences with mathematical mystery and beauty.

Why you should listen

Arthur Benjamin makes numbers dance. In his day job, he's a professor of math at Harvey Mudd College; in his other day job, he's a "Mathemagician," taking the stage in his tuxedo to perform high-speed mental calculations, memorizations and other astounding math stunts. It's part of his drive to teach math and mental agility in interesting ways, following in the footsteps of such heroes as Martin Gardner.

Benjamin is the co-author, with Michael Shermer, of Secrets of Mental Math (which shares his secrets for rapid mental calculation), as well as the co-author of the MAA award-winning Proofs That Really Count: The Art of Combinatorial Proof. For a glimpse of his broad approach to math, see the list of research talks on his website, which seesaws between high-level math (such as his "Vandermonde's Determinant and Fibonacci SAWs," presented at MIT in 2004) and engaging math talks for the rest of us ("An Amazing Mathematical Card Trick").

More profile about the speaker
Arthur Benjamin | Speaker | TED.com

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