- The University
- 10/02/2020
Willem Bouman sets his fifth mental calculation world record
His dream to become the first person ever to write at least ten five-digit numbers as the sum of four squares, came true this afternoon. With this achievement, Willem Bouman (born in 1939) from Alphen aan den Rijn established his fifth world record. The atmosphere in the movie theater of the Zwarte Doos got very suspenseful when it became clear that he would need two attempts.
A man with a background in humanities with a talent for mathematics, that is how he describes himself. That talent, he believes, also comes with the belief that it’s important to ‘try things.’ That is the reason for this attempt to set yet another remarkable record in arithmetic. It is his fifth world record; the previous four included‘ascending divisions’ and ‘calculate four consecutive prime numbers from a 16-digit number.’
Bouman was a guest at TU/e before, in 2009, when he extracted the cube root of an eighteen-digit number during a General Mathematics Seminar. He met Benne de Weger that day, and they’ve maintained regular contact ever since. And so, when Bouman was looking for a location to set a new record, it didn’t take long to find one. The record will be published on the site recordholders.org. That site is quite different from Guinessworldrecords.com, according to De Weger. “They at least pay serious attention to arithmetic records, which to me aren’t quite in the same category as the number of ballpoint pens in someone’s collection.” De Weger will serve as a referee, together with his colleagueMichiel Hochstenbach. They generated the numbers for the assignments via the calculation program Mathematica.
De Weger and Hochstenbach generated the numbers for two sets of assignments for him, using the calculation program Mathematica. This way, Bouman has two chances of providing the correct answers to ten consecutive assignments. It’s only after he is finished with the calculations – which he does mentally, he only writes down the answers – that the results are presented.
When the answer to the seventh assignment in set one turns out to be incorrect, the audience holds its breath. The atmosphere becomes suspenseful for a moment, until it turns out that the second set of ten assignments contains no incorrect answers. The record attempt was clocked at 4.54.77 minutes.
Bouman accounts for his mistake as follows: “This is what you’d call a mistake made out of haste. You squander your time now and then. But in hindsight everything is always clearer.” He also tells the audience that he makes calculations with the numbers on the license plates he sees on the road. “My brain is a calculation machine with a battery that never runs empty.”
King
In 2014, the retired car tire salesman received the Prix d'Excellence in Dresden. He received this prize because he was the only one who was able to factorize the number 278,353,657 into three non-consecutive prime numbers since Zacharias Dase in 1854. This earned him the nickname “the King of Prime.”
The King of Prime, incidentally, is an allround calculator. “I do everything; multiplying, dividing, involution, adding, subtracting. I don’t have a favorite number, only a favorite person: my wife.” It was she who decorated Bouman’s bowtie with prime numbers. And it was her cellphone that went off during the first record attempt today.
Bouman trains with the calculation program Mathematica on a daily basis. “I make twenty sums. According to a book I read, ‘The Great Mathematical Calculators’ by Steven Smith, it takes two things: a feeling for numbers and intensive training.”
No idea
The math wizard is a number practician, not a theoretician. “I own a book by Benne de Weger. It’s called ‘Elementary Number Theory and Asymmetric Cryptography’ and is filled with formulas. I have absolutely no idea what to do with it. But it is nice to share our thoughts.”
Bouman is a man of one-liners. For example: ‘Without math the only thing that grows is grass, and perhaps not even that.’ All he wants to say is that there’s no getting around math. “You come across it in all possible ways.” He has a hard time accepting it when he meets students who don’t even make an effort to calculate. His advice: “Take your calculating machine and throw in in the garbage can. Otherwise you become lazy as a dog and dumb as a doornail.”
Besides those life wisdoms, his head is filled with a fair number of bible verses and a generous amount of faith. But that doesn’t help him with his calculations. “There is no such thing as Protestant calculation,” he says. “What does exist however, is training.”
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