For today’s interview we visit the Netherlands to talk to Willem Bouman, a human calculator with more than 7 decades of experience with numbers! We first met in the 2012 World Cup in Gießen, and more recently while teaching at the Junior Mental Calculation World Cup in Bielefeld.
At age 81, he is still active in calculation, having recently written a book, delivered workshops, and been invited to a dinner hosted by the Dutch royal family.
When did you get involved in mental mathematics? Was it something you were always talented at, or was it self-taught at a later age?
According to the stories my mother told me, her friends always said “This is not a standard child—he is a special one”, because at the age of 1½ I knew all the letters of the alphabet, and at the age of 3 I could read the clock completely. Being in the dentist’s chair as a 4 year old boy, I said: “Now it is 11:55. In 5 minutes’ time it will be 12:00. The big hand indicates the minutes, the small hand indicates the hours”. In the 3rd class of the primary school, suddenly I knew all the 2×2 multiplications by heart. I consider this as a God-given talent, which I could later use automatically.
At the secondary school, I was taught extracting square roots, and then I saw the structure in the squares. During the less interesting lessons, I wrote all the numbers up to 1000 and wrote their squares beside. This is easier than one would think at first sight! What astonishes me the most is that the results were immediately saved in my memory. Learning about powering I discovered the structure there—to be read in my book.
When I was 20 years old, I met Wim Klein, who told me that only second, fourth and eight roots were possible. I explained to him my knowledge, he was completely flabbergasted and understood immediately what I had explained. Later on he used this knowledge for extracting very big roots: the 19th and 73th.
As for mathematics, I have never had much talent for it; I am only a simple mental calculator, though fortunately a good one! I describe my activities as a “mental calculator” rather than a “mathematician”.
What’s your favourite memory from your career so far in mental calculation?
Making acquaintance with other mental calculators at the competitions in 2006 was an eye-opener for me: Gert Mittring, Jan van Koningsveld, Robert Fountain and George Lane. None of them had secrets, they all were very open, answered all my questions and gave me the feeling to be welcome in this special world. This was an encouragement for me to continue training and diving deeper in the world of numbers.
The last time you competed was after your 70th birthday, making you one of the eldest competitors at the international level. What do you think is easier or more challenging for adults in mental calculation, compared to the young children?
An older person, if training continuously, gets more and more insight, which compensates the decreasing speed. I cannot say where the balance is, as I started with mental calculation at the top level when I was already 67 years old.
Are you planning to compete again in mental calculation?
I won’t compete again; the tournaments aim only at quantitative aspects. The winner is the person with the most correct answers in the shortest time. For myself: I aim at versatility, see my variation in my world records.
What mental calculation training are you doing in the past year?
Every day in the afternoon I practise addition, decimal square roots, writing 5 digit numbers as the sum of 4 squares, and Hectoc. I also try to find new structures in numbers.
What do you enjoy doing when you’re not thinking about numbers?
I am a railway modeller, and when working on that I don’t think about any numbers at all!
What advice would you give to anybody who wants to get involved at advanced mental calculation?
I am grateful to the Lord for the talent given to me. Yet I also speak about “The tyranny of the talent” and the rate of its influence in my being. Fortunately I am married 55 years, have 3 children and 6 grandchildren, I was a salesman during 28 years and I was a church elder for 28 years. This all made that I did not completely alienate from the social aspects of human life.
However, during my activity at the Junior Mental Calculation Club I have seen young men developing in a dangerous direction: better and better calculation with hardly any social ability. Let’s never forget: regardless the nature of ones talent and the level of it, if one does not develop social abilities, the result will be deep frustration!
Thank you Willem for sharing your experiences learning mental calculation and helping others with developing their own talents! If you want to read more by Willem, his book “Mental Calculation: An Art Apart” is available in English and Dutch. To contact him by email, you can use awap.bouman<at>casema.nl