Japanese use tiny beads of traditional abacus to calculate some gigantic sums
KYOTO, Japan — The caller read out the numbers at a speed evoking an auctioneer on fast-forward, each multidigit figure blurring into the next.
Within seconds, Daiki Kamino’s right arm shot up in the air, triumphant. Not only had he heard every number, but he also had tabulated them and arrived at the correct, 16-digit sum: 8,186,699,633,530,061.
He did it all on an abacus.
For this bit of mathematical virtuosity, Daiki, 16, a high school student from Hiroshima, Japan, was crowned champion in a dictation event at an annual tournament in Kyoto, where competitors pull off dazzling arithmetic feats simply by sliding tiny beads along rods set within modest wood frames.
Daiki is rangy and slightly awkward in that teenage boy kind of way. He loves Japanese comics known as manga, along with fantasy role-playing video games. But for the past eight years, he has spent up to three hours a day practicing on the abacus, or soroban in Japanese.
“There are times when I’m not in the mood,” he said. “But I start enjoying it once I start getting the right answers.
“I listen and move my fingers and repeat the numbers in my head,” he added, trying to explain how he could possibly do what he does. “As soon as I hear the unit like trillion or billion, I start to move my fingers.”
About 43,000 students take advanced soroban lessons at private schools in Japan, according to government estimates, although soroban associations say the number is higher. Many practitioners sit for exams to attain advanced qualifications known as kyu or dan, which are akin to belts in martial arts. Those who excel compete in national tournaments.
Showing the discipline of elite athletes, more than 800 contestants from across Japan, and a few from South Korea, gathered in an auditorium in Kyoto this month to put their skills to the test.
The youngest competitor was 8, the oldest 69. Multiplying and dividing numbers with as many as 16 digits, they sent rapid clickety-clacks rippling across the room like a summer downpour.
For some events, the contestants dispensed with the physical soroban and mentally pictured the beads as they completed long pages of calculations.
One winner, a 20-yearold college student, broke his own Guinness World Record by adding in his head 15 three-digit numbers that flashed on a large screen at the front of the auditorium — all in 1.64 seconds.
In the late 1970s, Japanese education officials, eager to bolster the population’s scientific and technological skills, significantly cut back on soroban instruction.
Today, textbooks mandated by the education ministry include only a couple of pages on the soroban. Students receive basic lessons for just two hours a year in third and fourth grade.
The soroban is made up of columns of beads, with each column standing for a place value such as ones, hundreds, thousands and so on. One bead on the top of each column is worth five, while four on the bottom of each column are worth one each. Students add, subtract, multiply and divide by sliding the beads up and down.
Some educators say the main reason for teaching soroban is to preserve traditional Japanese culture.
But Yukako Kawaguchi, 44, who runs one of the nearly 6,500 private soroban schools nationwide with her husband, Yoshiharu Kawaguchi, 47, said those who study the soroban intensively develop a sense of achievement.
On a recent afternoon during the first week of summer vacation for Japanese schoolchildren, about 30 students showed up at the Kawaguchis’ school in east Tokyo.
A group of 5- to 9-yearolds crammed into a compact room, pinching beads between their thumbs and index fingers, their heads bent over worksheets filled with calculations of escalating difficulty.
Niko Shibayama, 11, who has been studying soroban since kindergarten, used both her thumbs to click the beads, rat-a-tat. When she put the abacus aside to work on mental math, she swirled her pencil in the air and bobbed her head as if she were listening to music.
“It’s fun,” said Niko, who spends two afternoons and all morning Saturday at the school. “I am pretty competitive. So I never want to lose to anyone else.”