Google’s Emma Haruka Iwao and several coworkers broke the Guinness World Record for computing pi to 31 trillion digits, Engadget reports. They used cloud computing to break the previous world record by nine trillion digits. In celebration, here’s a trick to learn the first 24 digits of pi and to improve your number-memorizing skills.
March 14 is colloquially called “Pi Day” for its calendar date of 3/14, which represents the first three digits of the irrational number pi, 3.14. Iwao and her colleagues finished their calculations for Pi Day in January and recently announced their findings. According to the Engadget article, they began four months earlier and used a pi-benchmark calculation software called y-cruncher. Pi memorization is also a long-standing mathematics tradition; its first 24 digits come from a simple phonetic trick that can help you memorize long numbers—even if you need to read through the trick a couple of times.
Calculating Pi – The Major System: 1 through 5
The Major System is a memory device that assigns specific consonant sounds to each of the 10 numerical digits used worldwide, including zero. It’s a list that dates back 200 years to a German monk named Gregor von Feinaigle and French memory expert Aime Paris. “There are even mnemonics for learning this list,” Dr. Arthur T. Benjamin, Professor of Mathematics at Harvey Mudd College, said. “The following tips were given to me by my friend Tony Marloshkovips.” Remember that name.
“The one is the T or D sound, since when you draw a T your hand goes down once,” Dr. Benjamin said. “So a typewritten T has one down stroke, and if we can remember the ‘tuh’ sound, you should be able to remember the phonetically similar ‘duh’ sound.” Next, two is assigned the N sound since the typewritten N has two down strokes. The M sound represents three since it has three down strokes when written. This device ends with three, however, since four is translated to the R sound. Dr. Benjamin recommends remembering that when “four” is said out loud, it ends with an R.
To reach the halfway point, five is an L. “If you put the five on your hand and look between your index finger and your thumb you will see an L,” Dr. Benjamin said. “It’s cheap, but you’ll remember it, and that’s all that matters.”
So far, the numbers one through five can be translated to the vocal sounds T (or D), N, M, R and L. If these letters sound familiar—TN MRL—it’s because they’re the first half of Dr. Benjamin’s friend’s name “Tony Marloshkovips.”
The Major System: 6 through 0
The second half of the Major System continues the number-sound pairing of the first half. Unsurprisingly, if Tony Marloshkovips is our example, six is either SH, CH, or J depending on how one wishes to use it—”the sneezing sounds,” Dr. Benjamin calls them. “Six” and “sneezing” both start with an S.
Feinaigle and Paris matched the number seven with a K or G. “That’s a hard G, like ‘goat,’ not a soft G like ‘giraffe,'” Dr. Benjamin said. “The ‘giraffe G’ has a J sound and we’ve already used that with the number six. You can remember that the seven is the K sound by realizing that a K can be drawn as a combination of two sevens,” Dr. Benjamin said. G is also the seventh letter of the alphabet.
The number eight is the F or V sound, and Dr. Benjamin recommends imagining an ice skater doing a figure eight or that a lowercase cursive F looks a bit like a number eight. Nine is the P or B sound—”the puh or buh,” Dr. Benjamin said—and when mirrored the number nine looks like a capital P. Finally, zero gets the Z sound that the word “zero” begins with, or the S sound.
Calculating Pi – Putting It All Together
The Major System looks or sounds like T-N-M-R-L-SH-K-V-P-S, with those symbols standing in for 1-2-3-4-5-6-7-8-9-0. The easiest way to remember it is Tony Marloshkovips, or Tony Marloshkovips. By remembering this system and applying it to longer strings of numbers, we have a remarkable phonetic device to substitute easy words in for difficult digits. “We do this by inserting vowels anywhere we’d like among our consonants,” Dr. Benjamin said. “For example, suppose you needed to remember the number 491. How would you use the phonetic code? I would probably turn 491 into a ‘rabbit.'” Since four is R, nine is a P or B, and one is a T or D, he can select RBT and add the soft vowel sounds of A and I to form the word “rabbit.” Other words fit there as well—rapid, rabid, and so on.
So how does this add up to the first 24 digits of pi? They’re 3.14159265358979323846264, which, in the Major System, translates to “M TRTL PNCH L M L PK P M N MVR JNJR,” or—to quote Dr. Benjamin—”My turtle Poncho will, my love, pick up my new mover, Ginger.” Clearly, being memorable is easier than constructing a sentence often used in conversation.
Dr. Arthur T. Benjamin contributed to this article. Dr. Benjamin is Professor of Mathematics at Harvey Mudd College. He earned a Ph.D. in Mathematical Sciences from Johns Hopkins University in 1989. Professor Benjamin’s teaching has been honored repeatedly by the Mathematical Association of America (MAA).