What is the 13th root of . . .
From Charles Bremner in Paris
8368956688236956939837328662225645224726780466493836677497357558157303507570408962
52880238578315683768029349382010563433638555959315144504151494907094190977044493
05660268402771869624155688082648640933?
A FRENCH student was hailed yesterday as the greatest human calculator after
solving in under nine minutes the ultimate mental arithmetic challenge: finding
the 13th root of a 200-digit number.
Under the eye of official timekeepers, Alexis Lemaire, 24, a computer science
student from Reims, took 513 seconds to find the 16-digit number which,
multiplied by itself 13 times, produced a 200-digit sequence that had been
presented to him on a computer screen. He was not allowed to write or type.
Thirteenth roots have long been used as the test for records. The figure
is chosen because 13 is a prime number whose roots cannot be obtained by
combining those of other numbers.
M Lemaire, a shy, bearded student, amazed mental mathematicians in December
when he beat the record held by a German, Gert Mittring, for finding the
13th root of a 100-digit number. He did so in 3.62 seconds, against Herr
Mittring’s 13.55.
M Lemaire had been practising two hours a day since December for the 200-digit
challenge by memorising numbers that were powers of 13. “This is the
most difficult mental calculation in the world,” he said after his test,
which was organised by Sciences et Avenir magazine. “It is 100 times
more difficult than the record I broke in December because this time there
was only a one in 400,000 billion chance of getting the result by luck against
1 in 8 million in December.”
Before the challenge, Robert Fountain, a prizewinning mental calculator from
Northwich, Cheshire, was quoted on the 13th root internet site as saying:
“If Alexis Lemaire can achieve this in the presence of suitably qualified
witnesses then he must be regarded as the greatest ‘integer root
calculator’ in history.”
According to neurological scientists at Caen University, genius arithmeticians
use a different part of the brain from that used by average humans.
M Lemaire, who is learning 40 languages simultaneously in his spare time,
has promised to reveal part of his technique. His favourite numbers are 13,
67 and 37. Would-be challengers are being directed to the website
www.13throot.com
ANSWER: 2391481494636373
| Q. What is the 13th root of a hundred-digit number? Stumped?
This man did it in his head in 12 seconds
FROM ROGER BOYES IN BERLIN
Q. What is the 13th root of
7066437381674286102234008830240157375704233170702632731269721516000395709065419973141914549389684111?
A. 47,941,071
A MATHEMATICAL genius who struggled to pass his school exams has
outwitted computers by setting a world record for mentally calculating the
13th root of a hundred-digit number.
Gert Mittring, a 38-year-old German who has doctorates in psychology
and education, needed only 11.8 seconds to solve the puzzle.
The number was chosen at random by Albrecht Beutelspacher, director
of the Mathematics Museum at Giessen, near Frankfurt. Two umpires ensured
fair play. Spectators using electronic calculators were left lagging minutes
behind.
The 13th root is the number which when multiplied by itself 12 times
equals the number selected. The sum to find it is beyond the range of most
everyday calculators, although it can be done using a scientific calculator
with a "power" or exponentiation key.
The Guinness Book of Records may not accept the record, since it
no longer recognises root calculations of random numbers. "Some numbers are
easier to root than others," Sam Knight, its spokesman, said. Even so, the
German mathematical puzzler does hold 24 recognised world records.
The performance at Giessen on Tuesday night pushes back the boundaries
of mental calculation. The record for calculating the 13th root of a
hundred-digit figure was first set in 1975 by a Dutchman, Willem Klein; he
took 320 seconds. Klein refined his technique and by 1981 had managed to
get the calculation down to 89 seconds.
Few thought that this could be bettered, but Dr Mittring took up
the challenge after Klein's death in a car accident. He sliced 50 seconds
off Klein's achievement and yesterday came very close to a single- digit
time.
Although he struggled through school - his maths teacher described
him as "disturbingly unsatisfactory" - Dr Mittring has become an astonishing
example of the capacity of the human brain.
His achievements include memorising a 22-decimal figure inside 4
sec and 30 binary figures within 3 sec. He has also identified, within 38
sec, the days of the week of 20 random dates in a century. The days of the
week of 20 dates between the years 1600 and 2100 took him less than a minute
to name.
Dr Mittring emphasises that there are no tricks involved, no smoke
and mirrors. He does not even have to try very hard: 'When I'm given a number,
I just think of an elegant problem-solving algorithm and the result comes
straight away."
Dr Mittring, who was born in Bonn, lives in Carinthia, Austria. From
there, he runs a consultancy for the special needs of highly talented children
who, like him, disappoint their teachers at school.
November 25, 2004 |
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