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"

Arthur Benjamin face "Matemagie"

Filmed:
9,599,588 views

Într-o prezentare vioaie, matemagicianul Arthur Benjamin se întrece cu un grup de calculatoare pentru a găsi rădăcinile unor numere din 3 cifre, rezolva o dificilă ecuație mentală și ghicește câteva zile de naștere. Cum face toate astea? Vă va spune chiar el.
- 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 morningdimineaţă ladiesdoamnelor and gentlemendomnilor.
0
1000
1000
Bună ziua doamnelor și domnilor.
00:14
My nameNume is ArtArta BenjaminBenjamin, and I am a "mathemagicianmathemagician."
1
2000
3000
Ma numesc Art Benjamin si sunt un "matemagician"
00:18
What that meansmijloace is, I combinecombina my lovesiubește of mathmatematica and magicmagie
2
6000
3000
Asta inseamna ca eu combin doua pasiuni - matematica si magia,
00:21
to do something I call "mathemagicsmathemagics."
3
9000
2000
pentru a realiza ceea ce eu numesc "matemagie"
00:24
But before I get starteda început, I have a quickrapid questionîntrebare for the audiencepublic.
4
12000
3000
Inainte sa incepem, am o intrebare scurta pentru public.
00:27
By any chanceşansă, did anyoneoricine happenîntâmpla
5
15000
2000
Din intamplare,
00:29
to bringaduce with them this morningdimineaţă a calculatorcalculator?
6
17000
4000
a adus cineva in aceasta dimineata un calculator?
00:33
SeriouslySerios, if you have a calculatorcalculator with you, raisea ridica your handmână, raisea ridica your handmână.
7
21000
4000
Serios, daca aveti un calculator la voi, ridicati mana, ridicati mana.
00:37
I -- was -- your handmână go up?
8
25000
2000
Ma -- gandeam -- mana ta e sus?
00:39
Now bringaduce it out, bringaduce it out. AnybodyOricine elsealtfel?
9
27000
2000
Adu-l aici, adu-l aici. Altcineva?
00:41
I see, I see one way in the back.
10
29000
2000
Vad ... vad o mana ridicata departe in spate.
00:43
You sirdomn, that's threeTrei,
11
31000
2000
Dumneavoastra domnule, acum avem trei,
00:45
And anybodycineva on this sidelatură here?
12
33000
3000
Si cineva din partea aceasta?
00:48
OK, you over there on the aisleculoar. Would the fourpatru of you with calculatorscalculatoare
13
36000
2000
Da, tu cel de la margine. As vrea ca voi patru cu calculatoare
00:50
please bringaduce out your calculatorscalculatoare, then joina adera me up on stageetapă.
14
38000
3000
va rog, aduceti-va calculatoarele, apoi veniti langa mine pe scena.
00:53
And let's give these volunteersvoluntari a nicefrumos roundrundă of applauseaplauze.
15
41000
2000
Sa le oferim voluntarilor un rand generos de aplauze.
00:55
(ApplauseAplauze)
16
43000
3000
(Aplauze)
00:58
That's right. Now, sincede cand I haven'tnu au had the chanceşansă
17
46000
3000
Asa. Acum, pentru ca nu am avut ocazia
01:01
to work with these calculatorscalculatoare, I need to make sure
18
49000
3000
sa lucrez cu aceste calculatoare, trebuie sa ma asigur
01:04
that they are all workinglucru properlycum se cuvine.
19
52000
2000
ca toate functioneaza corect.
01:06
Would somebodycineva get us starteda început by givingoferindu- us a
20
54000
2000
Pentru inceput ar putea cineva sa ne dea
01:08
two-digitdouă cifre numbernumăr please?
21
56000
3000
un numar din doua cifre, va rog?
01:11
How about a two-digitdouă cifre numbernumăr?
22
59000
2000
Cine are un numar de doua cifre?
01:13
AudiencePublicul: 22.
23
61000
1000
Audienta: 22.
01:14
ArthurArthur BenjaminBenjamin: 22. And anothero alta two-digitdouă cifre numbernumăr, SirDomnule?
24
62000
2000
Arthur Benjamin: 22. Si inca un numar de doua cifre, domnule?
01:16
AudiencePublicul: 47.
25
64000
1000
Audienta: 47.
01:17
ABAB: MultiplyMultiplica 22 timesori 47, make sure you get 1,034,
26
65000
4000
AB: Inmultiti 22 cu 47 si verificati sa va dea 1,034,
01:21
or the calculatorscalculatoare are not workinglucru. Do all of you get 1,034? 1,034?
27
69000
5000
sau calculatoarele nu functioneaza. Aveti toti 1,034? 1,034?
01:26
WomanFemeie: No.
28
74000
1000
Femeia: Nu.
01:27
ABAB: 594. Let's give threeTrei of them a nicefrumos roundrundă of applauseaplauze there.
29
75000
4000
AB: 594. Sa le oferim celor trei un rand de aplauze.
01:31
(ApplauseAplauze)
30
79000
2000
(Aplauze)
01:33
Would you like to try a more standardstandard calculatorcalculator, just in casecaz?
31
81000
2000
Vreti sa incercati cu un calculator standard, in orice caz?
01:35
OK, great.
32
83000
2000
Bine, perfect.
01:37
What I'm going to try and do then --
33
85000
2000
Ce urmeaza sa fac --
01:39
I noticeînștiințare that tooka luat some of you a little bitpic of time to get your answerRăspuns.
34
87000
3000
Am observat ca v-a luat ceva timp pentru a ajunge la rezultat.
01:42
That's OK. I'll give you a shortcutscurtătură for multiplyingînmulțirea
35
90000
3000
Dar este in regula. Am sa va dau o scurtatura pentru
01:45
even fastermai repede on the calculatorcalculator.
36
93000
2000
inmultirea mai rapida pe calculator.
01:47
There is something calleddenumit the squarepătrat of a numbernumăr,
37
95000
2000
Exista radacina la patrat a unui numar,
01:49
whichcare mostcel mai of you know is takingluare a numbernumăr
38
97000
2000
ceea ce inseamna, dupa cum stiti, numarul
01:51
and multiplyingînmulțirea it by itselfîn sine.
39
99000
2000
imnultit cu el insusi.
01:53
For instanceinstanță, fivecinci squaredpătrat would be?
40
101000
2000
De exemplu, cinci la patrat ar fi?
01:55
AudiencePublicul: 25.
41
103000
1000
Audienta: 25.
01:56
ABAB: 25. Now, the way we can squarepătrat on mostcel mai calculatorscalculatoare --
42
104000
2000
AB: 25. Acum, felul in care ridicam la patrat cu majoritatea calculatoarelor --
01:58
let me demonstratedemonstra with this one --
43
106000
2000
am sa va arat cu acesta --
02:00
is by takingluare the numbernumăr, suchastfel de as fivecinci,
44
108000
2000
este tastarea numarului, adica cinci,
02:02
hittinglovind "timesori" and then "equalseste egală,"
45
110000
3000
apasand "inmultit" si apoi "egal",
02:05
and on mostcel mai calculatorscalculatoare that will give you the squarepătrat.
46
113000
3000
iar pe multe calculatoare ar trebui sa va dea radacina.
02:08
On some of these ancientvechi RPNRPN calculatorscalculatoare,
47
116000
2000
Pe unele calculatoare mai vechi,
02:10
you've got an "x squaredpătrat" buttonbuton on it,
48
118000
2000
aveti un buton "x la patrat" pe el,
02:12
will allowpermite you to do the calculationcalcul even fastermai repede.
49
120000
3000
va va permite sa calculati chiar mai repede.
02:15
What I'm going to try and do now is to squarepătrat, in my headcap,
50
123000
3000
Ceea ce voi incerca acum, este sa ridic la patrat, in cap,
02:18
fourpatru two-digitdouă cifre numbersnumerele
51
126000
2000
patru numere de doua cifre
02:20
fastermai repede than they can do on theiral lor calculatorscalculatoare, even usingutilizând the shortcutscurtătură methodmetodă.
52
128000
4000
mai rapid decat pot ei calcula, chiar folosind metoda rapida.
02:24
What I'll use is the secondal doilea rowrând this time, and I'll get fourpatru of you --
53
132000
2000
Voi folosi al doilea rand de aceasta data, si as dori de la voi --
02:26
one, two, threeTrei, fourpatru -- to eachfiecare yellstrigăt out a two-digitdouă cifre numbernumăr,
54
134000
3000
unu, doi, trei, patru -- sa strigati cate un numar de doua cifre,
02:29
and if you would squarepătrat the first numbernumăr,
55
137000
4000
si as vrea ca tu sa ridici la patrat primul numar,
02:33
and if you would squarepătrat the secondal doilea, the thirdal treilea and the fourthAl patrulea,
56
141000
2000
tu al doilea, al treilea si al patrulea,
02:35
I will try and racerasă you to the answerRăspuns. OK?
57
143000
3000
iar eu voi incerca sa va intrec. In regula?
02:38
So quicklyrepede, a two-digitdouă cifre numbernumăr please.
58
146000
3000
Deci repede -- un numar de doua cifre, va rog.
02:41
AudiencePublicul: 37.
59
149000
1000
Audienta: 37.
02:42
ABAB: 37 squaredpătrat, OK.
60
150000
1000
AB: 37 la patrat, da.
02:44
AudiencePublicul: 23.
61
152000
1000
Audienta: 23.
02:45
ABAB: 23 squaredpătrat, OK.
62
153000
2000
AB: 23 la patrat, da.
02:47
AudiencePublicul: 59.
63
155000
1000
Audienta: 59.
02:48
ABAB: 59 squaredpătrat, OK, and finallyin sfarsit?
64
156000
1000
AB: 59 la patrat, da, iar ultimul?
02:49
AudiencePublicul: 93.
65
157000
2000
Audienta: 93.
02:51
ABAB: 93 squaredpătrat. Would you call out your answersrăspunsuri, please?
66
159000
2000
AB: 93 la patrat. Imi puteti spune raspunsurile, va rog?
02:54
WomanFemeie: 1369. ABAB: 1369.
67
162000
2000
Femeia: 1369. AB: 1369.
02:56
WomanFemeie: 529.
68
164000
1000
Femeia: 529.
02:57
ABAB: 529.
69
165000
1000
AB: 529.
02:58
Man: 3481.
70
166000
1000
Barbatul: 3481.
02:59
ABAB: 3481.
71
167000
1000
AB: 3481.
03:00
Man: 8649.
72
168000
1000
Barbatul: 8649.
03:01
ABAB: Thank you very much.
73
169000
1000
AB: Va multumesc foarte mult.
03:02
(ApplauseAplauze)
74
170000
5000
(Aplauze)
03:07
Let me try to take this one stepEtapa furthermai departe.
75
175000
3000
Haideti sa mergem un pas mai departe.
03:10
I'm going to try to squarepătrat some three-digittrei cifre numbersnumerele this time.
76
178000
3000
Am sa ridic la patrat niste numere de trei cifre acum.
03:13
I won'tnu va even writescrie these down --
77
181000
2000
Nici nu o sa le mai scriu --
03:15
I'll just call them out as they're calleddenumit out to me.
78
183000
2000
o sa le scriu direct cand mi se spun.
03:17
AnyoneOricine I pointpunct to, call out a three-digittrei cifre numbernumăr.
79
185000
3000
Cel spre care arat cu degetul, striga un numar de trei cifre.
03:20
AnyoneOricine on our panelpanou, verifyverifica the answerRăspuns.
80
188000
2000
Oricine din juriu, verifica raspunsul.
03:22
Just give some indicationindicaţie if it's right.
81
190000
2000
Doar spuneti-mi daca e bine.
03:24
A three-digittrei cifre numbernumăr, sirdomn, yes?
82
192000
2000
Un numar din trei cifre, doumnule?
03:27
AudiencePublicul: 987.
83
195000
1000
Audienta: 987.
03:28
ABAB: 987 squaredpătrat is 974,169.
84
196000
3000
AB: 987 ridicat la patrat e 974,169.
03:31
(LaughterRâs)
85
199000
2000
(Rasete)
03:33
Yes? Good.
86
201000
2000
Da? Bun.
03:35
AnotherUn alt, anothero alta three-digittrei cifre --
87
203000
2000
Inca un numar de trei cifre --
03:37
(ApplauseAplauze)
88
205000
1000
(Aplauze)
03:38
-- anothero alta three-digittrei cifre numbernumăr, sirdomn?
89
206000
3000
-- inca un numar de trei cifre, domnule?
03:41
AudiencePublicul: 457.
90
209000
1000
Audienta: 457.
03:42
ABAB: 457 squaredpătrat is 205,849.
91
210000
3000
AB: 457 ridicat la patrat este 205,849.
03:45
205,849?
92
213000
2000
205,849?
03:47
Yes?
93
215000
2000
Da?
03:49
OK, anothero alta, anothero alta three-digittrei cifre numbernumăr, sirdomn?
94
217000
3000
Bun, inca, inca un numar de trei cifre, domnule?
03:52
AudiencePublicul: 321.
95
220000
1000
Audienta: 321.
03:53
ABAB: 321 is 103,041. 103,041.
96
221000
3000
AB: 321 este 103,041. 103, 041.
03:56
Yes? One more three-digittrei cifre numbernumăr please.
97
224000
3000
Da? Inca un numar de trei cifre, va rog.
03:59
AudiencePublicul: Oh, 722.
98
227000
2000
Audienta: umm, 722.
04:01
ABAB: 722 is 500 -- oohooh, that's a harderMai tare one.
99
229000
3000
AB: 722 este 500 -- uf, acesta e mai greu.
04:04
Is that 513,284?
100
232000
3000
raspunsul este 513,284?
04:07
WomanFemeie: Yes.
101
235000
1000
Femeia: Da.
04:08
ABAB: Yes? Oh, one more, one more three-digittrei cifre numbernumăr please.
102
236000
3000
AB: Da? Inca unul, inca un numar de trei cifre, va rog.
04:11
AudiencePublicul: 162.
103
239000
1000
Audienta: 162.
04:12
162 squaredpătrat is 26,244.
104
240000
4000
162 ridicat la patrat este 26,244.
04:16
Thank you very much.
105
244000
2000
Va multumesc foarte mult.
04:18
(ApplauseAplauze)
106
246000
6000
(Aplauze)
04:25
Let me try to take this one stepEtapa furthermai departe.
107
253000
3000
Hai sa incercam un pas mai departe.
04:28
(LaughterRâs)
108
256000
2000
(Rasete)
04:30
I'm going to try to squarepătrat a four-digitpatru cifre numbernumăr this time.
109
258000
3000
Am sa ridic la patrat un numar de patru cifre, acum.
04:33
Now you can all take your time on this; I will not beatbate you to the answerRăspuns on this one,
110
261000
3000
Puteti sa calculati linistiti; nu va voi da raspunsul mai rapid,
04:36
but I will try to get the answerRăspuns right.
111
264000
2000
dar am sa incerc sa va dau raspunsul corect.
04:38
To make this a little bitpic more randomîntâmplător, let's take the fourthAl patrulea rowrând this time,
112
266000
3000
Pentru a face mai aleatorie alegerea, am sa iau al patrulea rand acum,
04:41
let's say, one, two, threeTrei, fourpatru.
113
269000
3000
sa spunem, unu, doi, trei, patru.
04:44
If eachfiecare of you would call out a singlesingur digitcifre betweenîntre zerozero and ninenouă,
114
272000
2000
Spuneti va rog cate un singur numar de la zero la noua,
04:46
that will be the four-digitpatru cifre numbernumăr that I'll squarepătrat.
115
274000
3000
acesta va fi numarul nostru din patru cifre pe care il voi ridica la patrat.
04:49
AudiencePublicul: NineNouă.
116
277000
1000
Audienta: Noua.
04:50
ABAB: NineNouă.
117
278000
1000
AB: Noua.
04:51
AudiencePublicul: SevenŞapte. ABAB: SevenŞapte.
118
279000
1000
Audienta: Sapte. AB: Sapte.
04:52
AudiencePublicul: FiveCinci. ABAB: FiveCinci.
119
280000
1000
Audienta: Cinci. AB: Cinci.
04:53
AudiencePublicul: EightOpt. ABAB: EightOpt.
120
281000
1000
Audienta: Opt. AB: Opt.
04:55
9,758, this will take me a little bitpic of time, so bearurs with me.
121
283000
3000
9,758, imi va lua ceva timp, asteptati putin.
04:58
95,218,564?
122
286000
9000
95,218,564?
05:07
WomanFemeie: Yes.
123
295000
1000
Femeia: Da.
05:08
ABAB: Thank you very much.
124
296000
2000
AB: Va multumesc foarte mult.
05:10
(ApplauseAplauze)
125
298000
7000
(Aplauze)
05:18
Now, I would attemptatentat, încercare to squarepătrat a five-digit5 cifre numbernumăr --
126
306000
3000
Acum, as incerca sa ridic la patrat un numar din cinci cifre --
05:21
and I can --
127
309000
2000
si pot --
05:23
but unfortunatelydin pacate mostcel mai calculatorscalculatoare cannotnu poti.
128
311000
2000
dar din pacate multe calculatoare nu pot.
05:25
(LaughterRâs)
129
313000
2000
(Rasete)
05:27
Eight-digitOpt cifre capacitycapacitate -- don't you hateură that?
130
315000
3000
Spatiu pe opt biti -- nu urati asta?
05:30
So, sincede cand we'vene-am reachedatins the limitslimite of our calculatorscalculatoare --
131
318000
3000
Deci, cum am ajuns la limita calculatoarelor noastre --
05:33
what's that? Does yoursa ta go --
132
321000
3000
poftim? Al tau merge --
05:36
WomanFemeie: I don't know.
133
324000
1000
Femeia: Nu stiu.
05:37
ABAB: Does yoursa ta go highersuperior?
134
325000
2000
AB: Al tau merge mai sus?
05:39
Oh -- yoursa ta does?
135
327000
2000
Ah -- al tau?
05:41
Man: I can probablyprobabil do it.
136
329000
1000
Barbatul: Cel mai probabil pot.
05:42
ABAB: I'll talk to you latermai tarziu.
137
330000
2000
AB: O sa vorbim noi mai tarziu.
05:44
In the meanwhileîntre timp, let me concludeîncheia
138
332000
2000
Intre timp, as termina
05:46
the first partparte of my showspectacol by doing something a little trickiermai complicat.
139
334000
3000
prima parte a spectacolului meu prin a face ceva mai greu.
05:49
Let's take the largestcea mai mare numbernumăr on the boardbord here, 8649.
140
337000
3000
Hai sa luam cel mai mare numar de pe plansa, 8649.
05:52
Would you eachfiecare enterintroduce that on your calculatorcalculator?
141
340000
3000
Puteti introduce fiecare asta in calculator?
05:55
And insteadin schimb of squaringCuadratura it this time,
142
343000
2000
Dar in loc sa ridicati la patrat acum,
05:57
I want you to take that numbernumăr and multiplymultiplica it
143
345000
2000
As vrea sa luati numarul si sa il inmultiti
05:59
by any three-digittrei cifre numbernumăr that you want,
144
347000
3000
cu orice numar din trei cifre doriti,
06:02
but don't tell me what you're multiplyingînmulțirea by --
145
350000
2000
dar nu imi spuneti cu ce numar il inmultiti --
06:04
just multiplymultiplica it by any randomîntâmplător three-digittrei cifre numbernumăr.
146
352000
3000
doar inmultiti-l cu orice numar aleatoriu de trei cifre.
06:07
So you should have as an answerRăspuns eitherfie
147
355000
2000
Ar trebui sa aveti ca raspuns fie
06:09
a six-digitșase cifre or probablyprobabil a seven-digitSir numbernumăr.
148
357000
4000
un numar format din 6 cifre, sau poate 7.
06:13
How manymulți digitscifre do you have, sixşase or sevenȘapte?
149
361000
1000
Cate cifre are al tau, sase sau sapte?
06:14
SevenŞapte, and yoursa ta? WomanFemeie: SevenŞapte.
150
362000
2000
Sapte, iar al tau? Femeia: Sapte.
06:16
ABAB: SevenŞapte? SevenŞapte?
151
364000
3000
AB: Sapte? Sapte?
06:19
And, uncertainincert.
152
367000
2000
Deci, nesigur.
06:21
Man: Yeah.
153
369000
1000
Barbatul: Da.
06:22
ABAB: SevenŞapte. Is there any possibleposibil way that I could know
154
370000
2000
AB: Sapte. Ar fi cumva posibil sa stiu
06:24
what sevenȘapte digitcifre numbersnumerele you have? Say "No."
155
372000
3000
ce numar de sapte cifre aveti? Spuneti "Nu."
06:27
(LaughterRâs)
156
375000
2000
(Rasete)
06:29
Good. Then I shalltrebuie attemptatentat, încercare the impossibleimposibil --
157
377000
2000
Bun. Atunci am sa incerc imposibilul --
06:31
or at leastcel mai puţin the improbableimprobabil.
158
379000
2000
sau cel putitn improbabilul.
06:33
What I'd like eachfiecare of you to do is to call out for me
159
381000
2000
Ce as dori ca fiecare sa imi spuna
06:35
any sixşase of your sevenȘapte digitscifre, any sixşase of them,
160
383000
3000
oricare sase dintre cele sapte cifre, oricare sase,
06:38
in any orderOrdin you'dte-ai like.
161
386000
2000
in ce ordine doriti.
06:40
(LaughterRâs)
162
388000
1000
(Rasete)
06:41
One digitcifre at a time, I shalltrebuie try and determinea determina the digitcifre you've left out.
163
389000
5000
Cate o cifra pe rand, iar eu am sa incerc sa gasesc ultima cifra.
06:46
So, startingpornire with your seven-digitSir numbernumăr,
164
394000
2000
Deci, incepand cu numarul de sapte cifre,
06:48
call out any sixşase of them please.
165
396000
2000
spune-mi oricare sase cifre, te rog.
06:50
WomanFemeie: One, OK, 197042.
166
398000
6000
Femeia: Unu, da, 197042
06:56
ABAB: Did you leavepărăsi out the numbernumăr 6?
167
404000
1000
Ai omis cumva cifra 6?
06:57
WomanFemeie: Yes, ABAB: Good, OK, that's one.
168
405000
2000
Femeia: Da, AB: Bun, primul.
06:59
You have a seven-digitSir numbernumăr, call out any sixşase of them please.
169
407000
2000
Tu ai un numar de sapte cifre, spune-mi oricare sase te rog.
07:01
WomanFemeie: 44875.
170
409000
3000
Femeia: 44875.
07:04
ABAB: I think I only heardauzit fivecinci numbersnumerele. I -- wait -- 44875 --
171
412000
5000
AB: Cred ca am auzit doar cinci numere. 44875...
07:09
did you leavepărăsi out the numbernumăr 6?
172
417000
2000
ai omis numarul sase?
07:11
WomanFemeie: Yes. ABAB: SameAcelaşi as she did, OK. You've got a seven-digitSir numbernumăr --
173
419000
2000
Femeia: Da. AB: La fel ca ea, bun. Tu ai un numar de sapte cifre --
07:13
call out any sixşase of them loudtare and clearclar.
174
421000
3000
spune-mi oricare sase tare si clar.
07:16
Man: 079044.
175
424000
4000
Barbatul: 079044.
07:20
ABAB: I think you left out the numbernumăr 3?
176
428000
2000
AB: Cred ca ai omis numarul 3?
07:22
That's threeTrei. The oddsșanse of me gettingobtinerea all fourpatru of these right by randomîntâmplător guessingghicitul
177
430000
4000
Asta-l al treilea. Sansele ca eu sa ghicesc toate patru numerele corect
07:26
would be one in 10,000: 10 to the fourthAl patrulea powerputere.
178
434000
3000
ar fi una din 10,000: 10 la puterea a patra.
07:29
OK, any sixşase of them.
179
437000
2000
Bun, oricare sase dintre ele.
07:32
Really scrambleîncăierare them up this time, please.
180
440000
2000
Amesteca-le bine de data aceasta, te rog.
07:34
Man: 263972.
181
442000
4000
Barbatul: 263972.
07:38
ABAB: Did you leavepărăsi out the numbernumăr 7?
182
446000
2000
AB: Ai omis numarul 7?
07:40
And let's give all fourpatru of these people a nicefrumos roundrundă of applauseaplauze.
183
448000
2000
Haideti sa le acordam acestor oameni un rand de aplauze.
07:42
Thank you very much. (ApplauseAplauze)
184
450000
2000
Va multumesc foarte mult.
07:52
For my nextUrmător → numbernumăr --
185
460000
2000
Pentru numarul urmator --
07:54
(LaughterRâs)
186
462000
2000
(Rasete)
07:57
while I mentallymental rechargereîncărcare my batteriesbaterii,
187
465000
2000
pana imi incarc bateriile,
07:59
I have one more questionîntrebare for the audiencepublic.
188
467000
3000
am o intrebare pentru audienta,
08:02
By any chanceşansă, does anybodycineva here happenîntâmpla to know
189
470000
5000
Din intamplare, isi cunoaste cineva
08:07
the day of the weeksăptămână that they were bornnăscut on?
190
475000
3000
ziua saptamanii in care s-a nascut?
08:10
If you think you know your birthnaștere day, raisea ridica your handmână.
191
478000
4000
Daca va cunoasteti ziua de nastere, ridicati mana.
08:14
Let's see, startingpornire with -- let's startstart with a gentlemandomn first,
192
482000
3000
Hai sa vedem, incepem cu -- hai sa incepem cu un domn,
08:17
OK sirdomn, what yearan was it, first of all? That's why I startstart with a gentlemandomn first.
193
485000
3000
Bun domnule, ce an a fost, in primul rand? De asta incep cu un domn.
08:20
What yearan?
194
488000
1000
Ce an?
08:21
AudiencePublicul: 1953.
195
489000
1000
Audienta: 1953.
08:22
ABAB: 1953, and the monthlună?
196
490000
2000
AB: 1953, si luna?
08:24
AudiencePublicul: NovemberNoiembrie. ABAB: NovemberNoiembrie what?
197
492000
1000
Audienta: Noiembrie. AB: Noiembrie cat?
08:25
AudiencePublicul: 23rdRd.
198
493000
1000
Audienta: 23.
08:26
ABAB: 23rdRd -- was that a MondayLuni? AudiencePublicul: Yes.
199
494000
2000
AB: 23 -- a fost cumva o zi de Luni? Audienta: Da.
08:28
Yes, good. SomebodyCineva elsealtfel? Who elsealtfel would like --
200
496000
2000
Da, bun. altcineva? Cine mai vrea --
08:30
see I don't -- haven'tnu au seenvăzut any women'sFemei handsmâini up.
201
498000
2000
nu am vazut nicio doamna ridicand mana.
08:32
OK, it's -- how about you, what yearan?
202
500000
2000
Bun, este -- dar tu, ce an?
08:34
AudiencePublicul: 1949. ABAB: 1949, and the monthlună?
203
502000
2000
Audienta: 1949. AB: 1949, iar luna?
08:36
AudiencePublicul: OctoberOctombrie. ABAB: OctoberOctombrie what?
204
504000
1000
Audienta: Octombrie. AB: Octombrie cat?
08:37
AudiencePublicul: FifthA cincea.
205
505000
1000
Audienta: Cinci.
08:38
ABAB: FifthA cincea -- was that a WednesdayMiercuri?
206
506000
2000
AB: Cinci -- a fost o zi de Miercuri?
08:40
Yes, my -- I'll go way to the back right now, how about you?
207
508000
2000
Da, -- hai sa mergem mult in spate, tu?
08:42
YellTipa it out, what yearan? AudiencePublicul: 1959.
208
510000
2000
Striga mai tare, ce an? Audienta: 1959.
08:44
ABAB: 1959, OK -- and the monthlună?
209
512000
2000
AB: 1959, bun -- iar luna?
08:46
AudiencePublicul: FebruaryFebruarie.
210
514000
2000
Audienta: Februarie.
08:48
ABAB: FebruaryFebruarie what? AudiencePublicul: SixthA şasea.
211
516000
2000
AB: Februarie cat? Audienta: Sase.
08:50
ABAB: SixthA şasea -- was that a FridayVineri? AudiencePublicul: Yes.
212
518000
2000
AB: Sase -- a fost o zi de Vineri? Audienta: Da.
08:52
Good, how about the personpersoană behindin spate her?
213
520000
2000
Bun, ia sa vedem, persoana din spatele ei?
08:54
Call -- call -- what yearan was it?
214
522000
2000
Spune -- spune -- in ce an?
08:56
AudiencePublicul: 1947. ABAB: 1947, and the monthlună?
215
524000
2000
Audienta: 1947. AB: 1947, iar luna?
08:58
AudiencePublicul: MayPoate. ABAB: MayPoate what?
216
526000
2000
Audienta: Mai. AB: Mai cat?
09:00
AudiencePublicul: SeventhA şaptea. ABAB: SeventhA şaptea -- would that be a WednesdayMiercuri?
217
528000
2000
Audienta: Sapte. AB: Sapte -- a fost cumva o zi de Miercuri?
09:02
AudiencePublicul: Yes.
218
530000
1000
Audienta: Da.
09:03
ABAB: Thank you very much.
219
531000
2000
AB: Va multumesc foarte mult.
09:05
(ApplauseAplauze)
220
533000
3000
(Aplauze)
09:09
AnybodyOricine here who'dcare ar like to know the day of the weeksăptămână they were bornnăscut?
221
537000
3000
Este cineva care ar dori sa stie ziua din saptamana cand s-a nascut?
09:12
We can do it that way.
222
540000
2000
Putem face si asa.
09:14
Of coursecurs, I could just make up an answerRăspuns and you wouldn'tnu ar fi know,
223
542000
2000
Bineinteles ca as putea inventa o zi, iar voi nu ati sti,
09:16
so I come preparedpregătit for that.
224
544000
2000
asa ca am venit pregatit pentru asta.
09:18
I broughtadus with me a bookcarte of calendarscalendare.
225
546000
2000
Am adus cu mine un almanah al calendarelor.
09:21
It goesmerge as fardeparte back into the pasttrecut as 1800, 'causepentru ca you never know.
226
549000
4000
Merge pana in anii 1800, pentru ca nu stii niciodata.
09:25
(LaughterRâs)
227
553000
2000
(Rasete)
09:27
I didn't mean to look at you, sirdomn --
228
555000
2000
Nu am vrut sa ma uit la tine, domnule --
09:29
you were just sittingședință there.
229
557000
2000
doar stateai acolo.
09:31
AnywayOricum, ChrisChris, you can help me out here, if you wouldn'tnu ar fi mindminte.
230
559000
3000
Oricum, Chris, ai putea sa ma ajuti putin aici?
09:34
This is a bookcarte of calendarscalendare, and I'll askcere --
231
562000
2000
Acesta e un almanah al calendarelor, si am sa intreb --
09:36
who was it that wanted to know theiral lor birthnaștere day? You sirdomn? OK.
232
564000
2000
cine voia sa isi cunoasca ziua de nastere? Tu, domnule? Bun.
09:38
What yearan was it, first of all?
233
566000
2000
Ce an a fost, in primul rand?
09:40
AudiencePublicul: 1966.
234
568000
1000
Audienta: 1966.
09:41
ABAB: '66 -- turnviraj to the calendarcalendar with 1966 --
235
569000
2000
AB: '66 -- da pagina la 1966 --
09:43
and what monthlună?
236
571000
2000
si ce luna?
09:45
AudiencePublicul: AprilAprilie. ABAB: AprilAprilie what?
237
573000
2000
Audienta: Aprilie. AB: Aprilie cat?
09:47
AudiencePublicul: 17thlea. ABAB: 17thlea -- I believe that was a SundayDuminica.
238
575000
2000
Audienta: 17. AB: 17 -- cred ca a fost o Duminica.
09:50
Can you confirma confirma, ChrisChris?
239
578000
2000
Poti sa ne confirmi, Chris?
09:52
ChrisChris AndersonAnderson: Yes. ABAB: Yeah, OK. I'll tell you what, ChrisChris:
240
580000
2000
Chris Anderson: Da. AB: Da, bun. Hai sa vedem, Chris,
09:54
as long as you have that bookcarte in frontfață of you,
241
582000
3000
daca tot esti cu almanahul in fata,
09:57
do me a favorfavoare, turnviraj to a yearan outsidein afara of the 1900s,
242
585000
4000
ajuta-ma, da pagina la un an in afara 1900'
10:01
eitherfie into the 1800s or way into the 2000s --
243
589000
3000
ori printre anii 1800 ori mult inspre 2000' --
10:04
that'llcare va be a much greatermai mare challengeprovocare for me.
244
592000
1000
ar fi o provocare mai mare pentru mine.
10:06
What yearan, ChrisChris, would you like?
245
594000
1000
Ce an, Chris?
10:07
CACA: 1824.
246
595000
1000
CA: 1824.
10:08
ABAB: 1824, OK.
247
596000
3000
AB: 1824, bun.
10:11
And what monthlună? CACA: JuneIunie.
248
599000
2000
Si ce luna? CA: Iunie.
10:13
ABAB: JuneIunie what? CACA: SixthA şasea.
249
601000
1000
AB: Iunie cat? CA: Sase.
10:15
ABAB: SixthA şasea -- was that a SundayDuminica?
250
603000
2000
AB: Sase -- era o zi de Duminica?
10:17
CACA: It was. ABAB: And it was cloudynoros.
251
605000
2000
CA: Da. AB: Si a fost innorat.
10:20
Good, thank you very much.
252
608000
2000
Bun, va multumesc foarte mult.
10:22
(ApplauseAplauze)
253
610000
6000
(Aplauze)
10:28
But I'd like to wrapîmpacheta things up now
254
616000
2000
Dar as dori sa terminam
10:30
by alludingaluzie to something
255
618000
3000
prin a reveni la ceva
10:33
from earliermai devreme in the presentationprezentare.
256
621000
2000
ce am discutat mai devreme.
10:35
There was a gentlemandomn up here who had a 10-digit-cifre calculatorcalculator.
257
623000
3000
Era un domn care avea un calculator pe 10-biti?
10:38
Where is he, would you standstand up,
258
626000
2000
Unde este, poate sa se ridice,
10:42
10-digit-cifre guy?
259
630000
2000
tipul cu 10-biti?
10:44
OK, well standstand up for me just for a secondal doilea,
260
632000
3000
Bun, stai in picioare pentru o secunda,
10:47
so I can see where you are.
261
635000
2000
sa pot vedea unde esti.
10:49
OK, oh, OK -- you have a 10-digit-cifre calculatorcalculator, sirdomn, as well?
262
637000
3000
Ah, bun -- si dumneavoastra aveti un calculator pe 10-biti, domnule?
10:52
OK, what I'm going to try and do, is to squarepătrat in my headcap
263
640000
4000
Bun, ceea ce am sa incerc acum, este sa ridic la patrat in minte
10:56
a five-digit5 cifre numbernumăr requiringcare necesită a 10-digit-cifre calculatorcalculator.
264
644000
3000
un numar de cinci cifre, necesitand un calculator pe 10-biti.
10:59
But to make my jobloc de munca more interestinginteresant for you, as well as for me,
265
647000
5000
Dar pentru a face totul mai interesant pentru voi, cat si pentru mine,
11:04
I'm going to do this problemproblemă
266
652000
2000
Am sa rezolv aceasta problema
11:06
thinkinggândire out loudtare.
267
654000
2000
gandind cu voce tare.
11:08
So you can actuallyde fapt, honestlysincer hearauzi
268
656000
3000
Iar voi veti auzi, serios,
11:11
what's going on in my mindminte
269
659000
2000
ceea ce imi trece mie prin cap
11:13
while I do a calculationcalcul of this sizemărimea.
270
661000
2000
in timp ce fac calcule de marimea aceasta.
11:15
Now, I have to apologizescuza to our magicianMagicianul friendprieten LennartLennart GreenVerde.
271
663000
3000
Acum, as dori sa ii cer scuze magicianului nostru Lennart Green.
11:18
I know as a magicianMagicianul we're not supposedpresupus to revealdezvălui our secretssecrete,
272
666000
4000
Stiu ca un magician nu ar trebui sa isi arate secretele,
11:22
but I'm not too afraidsperiat that people are going
273
670000
2000
dar nu cred ca oamenii vor incepe
11:24
to startstart doing my showspectacol nextUrmător → weeksăptămână, so --
274
672000
2000
sa reproduca spectacolul meu intr-o saptamana, asadar --
11:26
I think we're OK.
275
674000
2000
cred ca suntem in regula.
11:30
So, let's see, let's take a --
276
678000
3000
Asadar, haideti sa vedem, sa luam un --
11:33
let's take a differentdiferit rowrând of people, startingpornire with you.
277
681000
2000
haideti sa luam un alt rand, incepand de la tine.
11:35
I'll get fivecinci digitscifre: one, two, threeTrei, fourpatru --
278
683000
3000
Am nevoie de cinci cifre: una, doua, trei, patru --
11:38
oh, I did this rowrând alreadydeja. Let's do the rowrând before you,
279
686000
2000
ah, am incercat deja pe randul asta. Hai sa luam randul din fata voastra,
11:40
startingpornire with you sirdomn: one, two, threeTrei, fourpatru, fivecinci.
280
688000
3000
incepand cu tine: unu, doi, trei, patru, cinci.
11:43
Call out a singlesingur digitcifre -- that will be the five-digit5 cifre numbernumăr
281
691000
3000
Strigati cate o singura cifra -- acesta va fi numarul nostru de cinci cifre
11:46
that I will try to squarepătrat. Go aheadînainte.
282
694000
2000
pe care il voi ridica la patrat. Haideti.
11:48
AudiencePublicul: FiveCinci. ABAB: FiveCinci.
283
696000
2000
Audienta: Cinci. AB: Cinci
11:50
AudiencePublicul: SevenŞapte. ABAB: SevenŞapte.
284
698000
1000
Audienta: Sapte: AB: Sapte.
11:51
AudiencePublicul: SixŞase. ABAB: SixŞase.
285
699000
1000
Audienta: Sase. AB: Sase.
11:52
AudiencePublicul: EightOpt. ABAB: EightOpt.
286
700000
2000
Audienta: Opt. AB: Opt.
11:54
AudiencePublicul: ThreeTrei. ABAB: ThreeTrei.
287
702000
2000
Audienta: Trei. AB: Trei.
11:56
57,683
288
704000
3000
57,683
12:01
squaredpătrat. YuckLa naiba.
289
709000
2000
la patrat. Bleah.
12:03
Let me explainexplica to you how
290
711000
2000
Am sa incerc sa va explic
12:05
I'm going to attemptatentat, încercare this problemproblemă.
291
713000
3000
cum am sa abordez aceasta problema.
12:08
I'm going to breakpauză the problemproblemă down into threeTrei partspărți.
292
716000
3000
Am sa incep prin a imparti problema in trei parti.
12:11
I'll do 57,000 squaredpătrat,
293
719000
2000
Am sa fac 57,000 la patrat,
12:13
plusla care se adauga 683 squaredpătrat,
294
721000
3000
plus 683 la patrat,
12:17
plusla care se adauga 57,000 timesori
295
725000
3000
plus 57,000 inmultit cu
12:20
683 timesori two.
296
728000
2000
683 inmultit cu doi.
12:22
AddAdauga all those numbersnumerele togetherîmpreună,
297
730000
2000
Adun toate aceste numere,
12:24
and with any lucknoroc, arriveajunge at the answerRăspuns.
298
732000
3000
si cu putin noroc, voi ajunge la rezultat.
12:28
Now, let me recaprecapitulare.
299
736000
2000
Acum, hai sa recapitulam.
12:31
Thank you.
300
739000
2000
Multumesc.
12:34
While I explainexplica something elsealtfel --
301
742000
2000
Intre timp am sa explic altceva --
12:37
-- I know, that you can use, right?
302
745000
2000
-- stiu ca poti folosi, nu?
12:40
While I do these calculationcalcul[s],
303
748000
2000
Cat timp fac aceste calcule,
12:42
you mightar putea hearauzi certainanumit wordscuvinte,
304
750000
2000
veti auzi niste cuvinte cheie,
12:44
as opposedopus to numbersnumerele, creepfluaj into the calculationcalcul.
305
752000
4000
care pe langa numere, vor aparea in calcule.
12:48
Let me explainexplica what that is.
306
756000
1000
Hai sa va explic ce inseamna.
12:49
This is a phoneticfonetic codecod,
307
757000
2000
Reprezinta un cod fonetic,
12:51
a mnemonicmnemonic devicedispozitiv that I use,
308
759000
2000
un dispozitiv mnemotic pe care il folosesc,
12:53
that allowspermite me to convertconvertit numbersnumerele into wordscuvinte.
309
761000
3000
care imi permite sa transform numere in cuvinte.
12:56
I storemagazin them as wordscuvinte, and latermai tarziu on retrieveprelua them as numbersnumerele.
310
764000
3000
Le memorez ca si cuvinte, iar apoi le transform in numere.
12:59
I know it soundssunete complicatedcomplicat; it's not --
311
767000
2000
Stiu ca suna complicat; dar nu e --
13:01
I just don't want you to think you're seeingvedere something out of "RainPloaie Man" here.
312
769000
3000
Vreau doar sa stiti ca nu vedeti o scena din "Rain Man" acum.
13:04
(LaughterRâs)
313
772000
2000
(Rasete)
13:06
There's definitelycategoric a methodmetodă to my madnessnebunie --
314
774000
2000
Sigur exista o metoda in nebunia mea --
13:08
definitelycategoric, definitelycategoric. Sorry.
315
776000
2000
sigur, sigur. Scuze.
13:10
(LaughterRâs)
316
778000
3000
(Rasete)
13:14
If you want to talk to me about ADHDADHD afterwardsdupă aceea,
317
782000
2000
Daca doriti sa discutam despre sindromul ADHD dupa aceea,
13:16
you can talk to me then. All right --
318
784000
2000
putem vorbi atunci. Asadar --
13:18
by the way, one last instructioninstrucție,
319
786000
2000
chiar, o ultima rugaminte,
13:20
for my judgesjudecători with the calculatorscalculatoare -- OK, you know who you are --
320
788000
3000
pentru cei din juriu, cu calculatoarele -- bun, stiti cine suntet --
13:23
there is at leastcel mai puţin a 50 percentla sută chanceşansă
321
791000
3000
exista cel putin 50 la suta sansa
13:26
that I will make a mistakegreşeală here.
322
794000
3000
ca eu sa gresesc.
13:29
If I do, don't tell me what the mistakegreşeală is;
323
797000
3000
Daca gresesc, nu imi spuneti ce gresala am facut;
13:32
just say, "you're closeînchide," or something like that, and I'll try and figurefigura out the answerRăspuns --
324
800000
3000
doar spuneti "pe aproape", sau ceva de genul acesta, iar eu am sa incerc sa rezolv --
13:35
whichcare could be prettyfrumos entertainingdistractiv in itselfîn sine.
325
803000
3000
ceea ce ar putea fi interesant.
13:39
If, howeverin orice caz, I am right,
326
807000
2000
Daca, totusi, am dreptate,
13:41
whateverindiferent de you do, don't keep it to yourselftu, OK?
327
809000
3000
orice ati face, nu tineti doar pentru voie, da?
13:44
(LaughterRâs)
328
812000
1000
(Rasete)
13:45
Make sure everybodytoata lumea knowsștie that I got the answerRăspuns right,
329
813000
2000
Fiti siguri ca toata lumea stie ca am gasit raspunsul corect,
13:47
because this is my bigmare finishfinalizarea, OK.
330
815000
3000
pentru ca este marele meu final. Bun.
13:50
So, withoutfără any more stallingîn scădere,
331
818000
3000
Asadar, fara a mai trage de timp,
13:53
here we go.
332
821000
3000
sa incepem.
13:56
I'll startstart the problemproblemă in the middlemijloc, with 57 timesori 683.
333
824000
2000
Am sa incep cu problema din mijloc, cu 57 inmultit cu 683.
13:58
Now, 57 timesori 68 is 3,400, plusla care se adauga 476 is 3876,
334
826000
3000
Acum, 57 inmultit cu 68 este 3,400, plus 476 da 3876,
14:01
that's 38,760 plusla care se adauga 171,
335
829000
3000
adica 38,760 plus 171,
14:04
38,760 plusla care se adauga 171 is 38,931.
336
832000
3000
38,760 plus 171 este 38,931.
14:07
38,931; doubledubla that to get 77,862.
337
835000
4000
38,931; dublam asta si obtinem 77,862.
14:11
77,862 becomesdevine cookiecookie-ul fissionfisiune,
338
839000
2000
77,862 devine "cookie fission",
14:13
cookiecookie-ul fissionfisiune is 77,822.
339
841000
4000
"cookie fission" este 77,822.
14:17
That seemspare right, I'll go on. CookieCookie-ul fissionfisiune, OK.
340
845000
2000
Pare in regula, sa continuam. "Cookie fission", bun.
14:19
NextUrmătoarea, I do 57 squaredpătrat, whichcare is 3,249, so I can say,
341
847000
4000
Apoi, calculez 57 la patrat, care este 3,249, deci pot spune,
14:23
threeTrei billionmiliard. Take the 249, addadăuga that to cookiecookie-ul, 249,
342
851000
5000
3 miliarde. Iau 249 si il adaug la "cookie", 249,
14:28
oopsOops, but I see a carrytransporta comingvenire --
343
856000
2000
ups, dar vad un posibil rest --
14:30
249 --
344
858000
2000
249 --
14:32
addadăuga that to cookiecookie-ul, 250 plusla care se adauga 77,
345
860000
2000
adaug asta la "cookie", 250 plus 77,
14:34
is 327 millionmilion --
346
862000
4000
este 327 de milioane --
14:38
fissionfisiune, fissionfisiune, OK, finallyin sfarsit, we do 683 squaredpătrat,
347
866000
2000
"fission", "fission", bun, in sfarsit, facem 683 la patrat,
14:41
that's 700 timesori 666, plusla care se adauga 17 squaredpătrat
348
869000
2000
adica 700 inmultit cu 666 plus 17 la patrat,
14:43
is 466,489, revRev up if I need it,
349
871000
3000
adica 466,489, rotesc daca am nevoie,
14:46
revRev up, take the 466,
350
874000
2000
rotesc, iau 466,
14:48
addadăuga that to fissionfisiune, to get,
351
876000
2000
adaug asta la "fission" si obtin,
14:50
oh geeGee --
352
878000
2000
of, vai --
14:54
328,489.
353
882000
4000
328,489.
14:58
AudiencePublicul: Yeah!
354
886000
1000
Audienta: Daa!
14:59
ABAB: Good.
355
887000
1000
AB: Bun.
15:00
(ApplauseAplauze)
356
888000
1000
(Aplauze)
15:01
Thank you very much.
357
889000
2000
Va multumesc foarte mult.
15:03
I hopesperanţă you enjoyedsa bucurat mathemagicsmathemagics. Thank you.
358
891000
2000
Sper ca v-a placut "matemagia". Va multumesc
15:05
(ApplauseAplauze)
359
893000
4000
(Aplauze)
Translated by Gabriel Mirea
Reviewed by Alex Ghioiu

▲Back to top

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

Data provided by TED.

This site was created in May 2015 and the last update was on January 12, 2020. It will no longer be updated.

We are currently creating a new site called "eng.lish.video" and would be grateful if you could access it.

If you have any questions or suggestions, please feel free to write comments in your language on the contact form.

Privacy Policy

Developer's Blog

Buy Me A Coffee