In Fast Figuring, She Plays It by the Numbers

SUNNYVALE, Calif. — Shakuntala Devi is a distracting passenger to have in your car.

The problem is that there are all those numbers on the license plates of the cars in other lanes.

“Look, there’s 720,” Devi says, as if she has just seen an old friend. Riding the freeway from Sunnyvale on an errand to San Francisco, she produced a piece of paper and pen and began playing with the number. In an instant, she had the answer: 1 x 2 x 3 x 4 x 5 x 6 equals 720.

If that answer was a snap, so is multiplying two 13-digit numbers; or coming up with the root of 2,373,927,704 (the answer is 1,334); or naming the date on which every Thursday will fall in 1989, or, for that matter, any other day or any other year--past or future.

Devi, 43, is a sari-clad diva of numbers, a math prodigy who can calculate as fast and accurately as any hand-held contraption. She is one of those rare people who somehow--even she does not know how--possesses a skill with figures that amazes computer wizards, intrigues academics and dumbfounds those of us who have difficulty balancing checkbooks.

She is in the Guinness Book of World Records for a 1980 feat at a London university--multiplying two 13-digit numbers: 7,686,369,774,870 by 2,465,099,745,779. In 28 seconds. The answer:

18,947,668,177,995,426,462,773,730.

In 1977, she came up with the 23rd root of a 201-digit number in 50 seconds--faster than a powerful Univac computer, although since then, some people have scoffed that the computer would have won if only it had been properly programmed.

A Brahman from Bangladore, India, she takes her act on the road worldwide for several months each year. She was in the Silicon Valley most recently, performing at Stanford University, Cal State San Jose and at a computer company, Excelan. The outgoing and witty Devi was due in Los Angeles today.

Along the way, Arthur R. Jensen, professor of educational psychology at UC Berkeley, persuaded her to stop by his laboratory so he could study her.

Jensen said Devi’s skills with numbers are like those of a writer who does not think about the location of typewriter keys, or a musician who reads music and simultaneously sounds the correct notes. “The actual calculations are almost automatic,” he said.

After watching her both at Stanford and in his lab, Jensen concluded: “No one knows exactly how she does these things. I don’t think she knows.” He is, however, certain that “it’s not any kind of magic trick.”

Jensen tried to stump her by asking the day of the week for Jan. 30, 1948. It was, she answered in an instant, a Friday, and then noted its significance, the day Mahatma Gandhi was assassinated.

Her technique offers little clue to her ability. Before a performance, she clears her mind by lounging and shunning television, books and conversation. She must see the number on a blackboard or on paper, but does not like the numbers broken up by commas. Smaller numbers are harder to dissect than larger ones. She apologized for taking roughly five seconds to come up with the cube root of 131.

“It’s 5.09, or .08. It’ll be approximate,” she said.

One of Devi’s explanations for her ability is one that her mother suggested. As an infant, Devi swallowed the family’s small clay likeness of Ganesh, the Hindu god of wisdom, including mathematics. She prays daily at an altar of flowers, incense and a likeness of Ganesh, and in deference to the deity, will not venture to Communist countries. She fears that Ganesh might take away her gift if she goes to a land “where they don’t believe in God.”

Travels World Performing

She first displayed her flair for numbers as a toddler and became part of her father’s magic act in India. The theatrics learned in the act serve her well as she travels the world performing.

“You’d expect someone who could do what she does to be a little nerdy. She isn’t nerdy at all. She worked the crowd,” said Vish Mishra, vice president of Excelan, the San Jose computer company where she performed. Excelan paid her $1,000 for a one-hour performance.

“The computer people are fascinated that a human mind can do this,” Mishra said. “We’ve got brilliant people . . . mathematicians, and they wonder how can it be done.”

OFF THE TOP OF YOUR HEAD . . .

From the speedy mental calculation file of math whiz Shakuntala Devi: 28 Seconds

7,686,369,774,870

X 2,465,099,745,779

18,947,668,177,995,426,462,773,730 10 Seconds

Figure the Cube Root of

2,373,927,704

1,334 40 Seconds

Figure the 7th Root of

455,762,531,836,562,695,930,666,032,734,375

46,295