Ancient Japanese Math Exercises Brain

K Y O T O, Japan, Oct. 30 -- The contestants sit hunched over baretables, some in sweatshirts, some in neckties. A small audiencewatches quietly, while judges pace the floor in wait for aresponse.

Suddenly, a teenager’s hand shoots up and a shout breaks thesilence. “Done!” he calls out, and passes his answer sheet to amoderator.

Within seconds, Hiroaki Tsuchiya has multiplied — in his head —a list of numbers that would make an accountant’s head spin. Howdoes he do it? On an imaginary abacus, just as merchants, studentsand others have done throughout Asia for centuries.

Hours of Practice

Today, despite computers and calculators, the technique survivesas a strenuous workout for the brain. Teachers say almost anyonecan master it if they start young, although it takes hours ofpractice, mental dexterity and Herculean powers of concentration.

“If you space out, you lose,” said Tsuchiya, who at age 13recently became the youngest winner of a Kyoto tournament whereJapan’s best mental mathematicians display their amazing feats.

Tsuchiya, for example, takes only a few moments to solve aproblem like 992.587318 divided by 5,647.723. And he has to go tothe final digit of the answer: 0.17575000013279688115015555826658.

Called “anzan,” which translates roughly as “mentalcalculation,” the technique springs from an age when the easiestway to work with large numbers was to use an abacus, a manualcalculator introduced to Japan from China in the 1500s.

The box-shaped instrument is made of beads that serve ascounters, which users push back and forth along metal rods,clicking their way through cube roots, addition and subtraction,long division.

Quick But Not So Easy

But skilled abacus users often find it easier to just imaginethe beads rather than physically move them.

This is anzan, and those who master it can work faster than aclerk on an adding machine.

“Instead of thinking of the number one, imagine an apple inyour pocket. It has shape, it’s concrete.” said Koji Suzuki, aTokyo abacus instructor. “In anzan, we try to see the beads.”