It's math, it's magic, it's mathemagics

Arthur Benjamin combines his two loves, math and magics, into a show called Mathemagics. (Kevin Mapp Photo)

Quick! In two seconds or less, can you tell me what day of the week May 16, 1808 was?

One Mississippi, two Mississippi.

For most people, such a demand would seem all but impossible. You’d have to be some kind of mathematical magician to figure that one out.

Arthur Benjamin, a math professor at Harvey Mudd College in Claremont, California, is exactly that. He’s combined math and magic into what he calls “mathemagics.” (The answer is Monday.)

Hosted by the Department of Mathematics and Statistics, Dr. Benjamin brought his mathemagics show to Halifax recently. The lecture took place in Alumni Hall, University of King’s College. Dr. Benjamin, who the Los Angeles Times says "talks like a performer, acts like a magician and multiplies faster than a calculator," mystified a packed crowd with his lightning fast arithmetic.

After perplexing the crowd with an elaborate card trick, he asked volunteers with calculators to verify his answers. He began by squaring two-, three- and four-digit numbers before the answers appeared on the calculators. He then pinpointed the day of the week anyone in the audience was born only seconds after hearing the day, month and year of birth. He continued to awe as he gave specific days of the week for dates more than a century in the past and in the future.

Dr. Benjamin strays from tradition and explains his tricks, to show people it’s not magic, but methods he’s devised to perform fast calculations.

“I actually prefer to break the magician’s rule and explain to you what you’ve seen me do up here,” he said, inviting the audience to ask him questions. “Will you come with me to Vegas?” one man shouted. After a good laugh, Dr. Benjamin passed on the request, but made good on another when he explained how he was able to remember the 100 digits of pi (π).

(3.14159265358979323846 … and that’s just to get you started.)

The secret to mathemagics is simple, or so he says. He uses a phonetic code to remember π, and a numeric code, applied to months and days, to quickly tell him what day your birthday falls on. He explained these codes provide correct answers, simplify the process and can be done by anyone. “Call out your credit card numbers,” he said jokingly while explaining anything can be remembered with codes.

As for quickly finding the square of a number, he said he multiplies from left to right, rather than the traditional method of right to left, giving him the answer faster. 

For his grand finale. he figured out the square of a five-digit number, 57,682. Calculating out loud while the crowd watched in awe, he successfully arrived at 3,327,213,124 in about 30 seconds.

Dr. Benjamin astonished the room, filled with people of all ages, including math majors, PhD students and math professors with his quick solutions. His enthusiastic and involving presentation inspired even the math-impaired to get excited about mathematics.

Dr. Benjamin’s book, Secrets of Mental Math: The Mathemagician's Guide to Lightning Calculation and Amazing Math Tricks, explains his methods so anyone can do them. He’s appeared on The Today Show and has been profiled in The New York Times, People and USA Today.

LINK: To order Secrets of Mental Math, visit Dr. Benjamin's website.
SEE VIDEO: Arthur Benjamin's Mathemagics show