Mnemonic

Mnemonic, pronounced nee'monikos, is "A device, such as a formula or rhyme, used as an aid in remembering."

Examples of Mnemonics:

PI

Poe, E.: Near a Raven. Midnights so dreary, tired and weary.

Silently pondering volumes extolling all by-now obsolete lore.

During my rather long nap-the weirdest tap!

An ominous vibrating sound disturbing my chamber's antedoor.

'This,' I whispered quietly, 'I ignore.'

Perfectly, the intellect remembers: the ghostly fires, a glittering ember.

Inflamed by lightning's outbursts, windows cast penumbras upon this floor.

Sorrowful, as one mistreated, unhappy thoughts I heeded:

That inimitable lesson in elegance--Lenore--

Is delighting, exciting... nevermore.



e

Examples of e mnemonics (Gardner 1959, 1991) include:

"By omnibus I traveled to Brooklyn" (6 digits).

"To disrupt a playroom is commonly a practice of children" (10 digits).

"It enables a numskull to memorize a quantity of numerals" (10 digits).

"I'm forming a mnemonic to remember a function in analysis" (10 digits).

"He repeats: I shouldn't be tippling, I shouldn't be toppling here!" (11 digits).

"In showing a painting to probably a critical or venomous lady, anger dominates. O take guard, or she raves and shouts" (21 digits). Here, the word "O" stands for the number 0.

A much more extensive mnemonic giving 40 digits is

"We present a mnemonic to memorize a constant so exciting that Euler exclaimed: '!' when first it was found, yes, loudly '!'. My students perhaps will compute , use power or Taylor series, an easy summation formula, obvious, clear, elegant!"

(Barel 1995). In the latter, 0s are represented with "!". A list of mnemonics in several languages is maintained by A. P. Hatzipolakis.

Josephus Problem

"From numbers' aid and art, never will fame depart."

"Rex paphi cum gente bona dat signa serena" (Ball and Coxeter 1987).