A comprehensive mnemonic system called PAO (Person/Action/Object) for remembering pairs of digits from 00-99 is described in Moonwalking with Einstein: The Art and Science of Remembering Everything by Joshua Foer. His blog is at http://joshuafoer.com.
Check out a related blog by Josh Cohen at http://Mnemotechnics.org.
See also the Wikipedia references for the Mnemonic Major System and the Method of Loci.
The program 2Know (free download) was used to generate a long list of candidate objects for each number pair. See more notes below. The 100 images for this library with PAO descriptive captions can be played in a slideshow sequence at Picasaweb Albums.
Collage of one hundred PAO images for number pairs #00 to #99
Updates:
05/13 Changed #36 Little Match Girl person to Little Match Girl or Grandmother
04/29/2012: This system was uploaded today to Anki, a site for practicing memory training using electronic flash cards with optional images. The deck of one hundred flash cards can be downloaded freely by anyone who wants to study them or modify them to personal preference. After installing the Anki application program on your computer, run it and select File - Download - Shared Deck to view all of the memory packages available, listed in order of popularity by number of total downloads. By far the most popular deck with more than 154,000 downloads is a Japanese Kanji language set. Mandarin Chinese has a deck with almost 25,000 downloads and Spanish has one with about 15,000.
04/01/2012: Changed #59-lip-Daniel-dance to #59-lip-Nataraja-dance (the eternal cycle of Universe creation-destruction)
04/01/2012: Changed #83-foam-Fabian-laugh to #83-foam-Osel-Hita-Torres-laugh
03/31/2012: Created a separate directory of images cropped to 8x10 format in addition to the square crops, to obtain a collage photo suitable for printing as an 8x10 glossy by Snapfish without truncating any part of the full image. Three albums containing 100 Internet source images, 100 square cropped images and 100 8x10 cropped images were uploaded to Picasaweb Photo Albums. The captions for each image in each album were edited to name the Person-Action-Object from #00 to #99 . The source credits for each Internet image are hyperlinked in the ## column below.
02/03/12: Changed #14 Fertilize to Plant
11/21/11: Changed #24 Barbeque to Barbecue, #81 Walk over to Walk on, #86 Hook to Surf)
Photo Credits: The original Internet sources for these one hundred images are linked below in the ## column. "Fair use" is allowed for educational purposes such as teaching the Jwleaf PAO Mnemonic System. See the Wikipedia article on Fair Use for further details about the four balancing conditions applied in U.S. law.
05/13 Changed #36 Little Match Girl person to Little Match Girl or Grandmother
04/29/2012: This system was uploaded today to Anki, a site for practicing memory training using electronic flash cards with optional images. The deck of one hundred flash cards can be downloaded freely by anyone who wants to study them or modify them to personal preference. After installing the Anki application program on your computer, run it and select File - Download - Shared Deck to view all of the memory packages available, listed in order of popularity by number of total downloads. By far the most popular deck with more than 154,000 downloads is a Japanese Kanji language set. Mandarin Chinese has a deck with almost 25,000 downloads and Spanish has one with about 15,000.
04/01/2012: Changed #59-lip-Daniel-dance to #59-lip-Nataraja-dance (the eternal cycle of Universe creation-destruction)
04/01/2012: Changed #83-foam-Fabian-laugh to #83-foam-Osel-Hita-Torres-laugh
03/31/2012: Created a separate directory of images cropped to 8x10 format in addition to the square crops, to obtain a collage photo suitable for printing as an 8x10 glossy by Snapfish without truncating any part of the full image. Three albums containing 100 Internet source images, 100 square cropped images and 100 8x10 cropped images were uploaded to Picasaweb Photo Albums. The captions for each image in each album were edited to name the Person-Action-Object from #00 to #99 . The source credits for each Internet image are hyperlinked in the ## column below.
02/03/12: Changed #14 Fertilize to Plant
11/21/11: Changed #24 Barbeque to Barbecue, #81 Walk over to Walk on, #86 Hook to Surf)
Photo Credits: The original Internet sources for these one hundred images are linked below in the ## column. "Fair use" is allowed for educational purposes such as teaching the Jwleaf PAO Mnemonic System. See the Wikipedia article on Fair Use for further details about the four balancing conditions applied in U.S. law.
| ## | Person | Action (rationale) | Object | ## |
| 00 | The Snow Queen | Freeze (Kay kidnapped to the Queen's Ice Palace) | ice | 0 |
| 01 | Huckleberry Finn | Stub (bare toe) | toe | 1 |
| 02 | Godson Juan | Splash (favorite swimming hole El Pozo Bonito) | honey | 2 |
| 03 | Hansel & Gretel | Taste (gingerbread house) | home | 3 |
| 04 | Prince Siddhartha | Pull out (arrow from swan shot by Devadatta) | arrow | 4 |
| 05 | The Buddha | Illuminate | halo | 5 |
| 06 | Bodhidharma | Gaze (at wall 9 years. Carried one shoe walking back home) | shoe | 6 |
| 07 | Houdini | Hide | key | 7 |
| 08 | Jack & the Beanstalk | Climb | ivy | 8 |
| 09 | Judy Garland | Sing | rainbow | 9 |
| 10 | The Seventh Samurai | Shake | dice | 10 |
| 11 | Queequeg | Hurl
(harpoon from Moby Dick Pequod)
|
tattoo | 11 |
| 12 |
Francis of Assisi |
Pet (wore rope belt, having compassion for animals) | twine | 12 |
| 13 | Little Jack Horner | Insert | thumb | 13 |
| 14 | Johnny Appleseed | Plant | tree | 14 |
| 15 | Talu the Gibbon | Tickle | tail | 15 |
| 16 | Jim (Empire of the Sun) | Crawl
(Jim taking cover) |
ditch | 16 |
| 17 | Henry David Thoreau | Back off (retreat to Waldon Pond) | duck | 17 |
| 18 | Benoit Mandelbrot | Zoom in (fractal landscape, infinitely divisible) | tofu | 18 |
| 19 | Geronimo | Point | tepee | 19 |
| 20 | Brachiosaurus | Sneeze (Jurassic Park) | nose | 20 |
| 21 | The Nutcracker | Crack | nut | 21 |
| 22 | Job | Weep | onion | 22 |
| 23 | Dory (Finding Nemo) | Swim ("Just keep swimming ...") | Nemo | 23 |
| 24 | Hamlet | Barbecue ("bar-BE-cue", see Oscar Meyer ad "not to BE...") | wiener | 24 |
| 25 | Noah | Hammer | nail | 25 |
| 26 | Dana (Two Years Before the Mast) | Hoist | wench | 26 |
| 27 | E.T. | Stretch (telescoping neck) | neck | 27 |
| 28 | Edwin Hubble | Expand (the universe) | nova | 28 |
| 29 | Derren Brown | Twist | knob | 29 |
| 30 | Jean Baptiste Charbonneau | Flip | moose | 30 |
| 31 | Thor Heyerdahl | Float | moat | 31 |
| 32 | Galileo | Squint (single eye telescope) | moon | 32 |
| 33 | King Tut | Wrap | mummy | 33 |
| 34 | Gollum (Lord of the Rings) | Bite | moray | 34 |
| 35 | Bhaddali (MN 65) | Swallow (B. stubbornly ignored rules about eating) | mule | 35 |
| 36 | Little Match Girl or Grandmother | Scratch | match | 36 |
| 37 | Robinson Crusoe | Shade (but not Hide #07) | macaw | 37 |
| 38 | Kitchen Stories | Drink (Isaac's birthday party) | movie | 38 |
| 39 | Oscar Pistorius | Bounce (on springy blades, no feet) | amoeba | 39 |
| 40 | Mahatma Gandhi |
Spin
(homespun khadi) |
rice | 40 |
| 41 | Carl Linnaeus | Varnish (to preserve field specimens) | root | 41 |
| 42 | Tarzan of the Apes | Swing | rhino | 42 |
| 43 | Brother Paul Bernard | Kneel | room | 43 |
| 44 | Masai Warrior | Jump | warrior | 44 |
| 45 | John Henry | Explode | rail | 45 |
| 46 | Tarahumara | Jog (Copper Canyons of Chihuahua) | huarache | 46 |
| 47 | Abraham Lincoln | Cement | rock | 47 |
| 48 | Jetsun Milarepa | Listen (in Tibet, the roof of the world) | roof | 48 |
| 49 | Statue of Liberty | Fold | robe | 49 |
| 50 | The Lone Ranger | Corral | lasso | 50 |
| 51 | Marie Curie | Photograph | light | 51 |
| 52 | Emperor Ashoka of India | Roll (the wheel of dhamma) | lion | 52 |
| 53 | Mary Schoolgirl | Follow | lamb | 53 |
| 54 | Andres Segovia | Strum | lyre | 54 |
| 55 | Euclid | Flatten (two-dimensional plane geometry) | lily | 55 |
| 56 | Stand By Me | Peel | leech | 56 |
| 57 | Neanderthal | Wrestle (at some remote glacial cirque) | lake | 57 |
| 58 | Robert Frost | Subside (poem "Nothing gold can stay") | leaf | 58 |
| 59 | Nataraja | Dance | lip | 59 |
| 60 | Magnus Carlsen | Play | chess | 60 |
| 61 | Achilles | Sprint | cheetah | 61 |
| 62 | Jacob Marley | Drag | chain | 62 |
| 63 | Tinker Bell | Scatter (pixie dust) | chime | 63 |
| 64 | Miss Muffet | Sit on | chair | 64 |
| 65 | Venus (Boticelli) | Stand on | shell | 65 |
| 66 | Alan Turing | Count (cryptographic hash code) | hashish | 66 |
| 67 | Bill Gates | Autograph | check | 67 |
| 68 | Leo Tolstoy | Cut | sheaf | 68 |
| 69 | Ulysses | Sail | ship | 69 |
| 70 | Aesop | Squeeze (goose laying a golden egg) | goose | 70 |
| 71 | Benjamin Franklin | Fly | kite | 71 |
| 72 | Lewis & Clark | Paddle | canoe | 72 |
| 73 | Swami Sivananda | Toss (a comb out the window, free of attachments) | comb | 73 |
| 74 | John James Audubon | Sketch (American birds, but not #79 Color) | crow | 74 |
| 75 | Paul Revere | Blow (horn, the British are coming) | quail | 75 |
| 76 | Suchi | Curl up (little dog curls up like a cashew nut) | cashew | 76 |
| 77 | Jascha Heifetz | Fiddle (reciprocal movement like a cuckoo clock) | cuckoo | 77 |
| 78 | Sleeping Beauty | Wake up (and smell the coffee) | coffee | 78 |
| 79 | Pablo Picasso | Color (cubism) | cube | 79 |
| 80 | Ramana Maharshi | Go around (Arunachala Hill) | face | 80 |
| 81 | John Muir | Walk on (the Sierra Nevada) | foot | 81 |
| 82 | Stevie Wonder | Call (to say I love you) | phone | 82 |
| 83 | Osel Hita Torres | Laugh (at ephemeral nature of fame and glory) | foam | 83 |
| 84 | STS-125 Atlantis | Burn | fire | 84 |
| 85 | Thomas Edison | Sharpen | file | 85 |
| 86 | The Old Man & The Sea | Surf (in memory of Waianae, Oahu) | fish | 86 |
| 87 | Carl Sandburg | Tiptoe (fog comes on little cat feet) | fog | 87 |
| 88 | Yankee Doodle | March | fife | 88 |
| 89 | Walkabout | Clip on (trinkets at waist) | fob | 89 |
| 90 | The Carpenters | Ride (Ticket to Ride) | bus | 90 |
| 91 | Peer Gynt | Lie on (weary end of travels finally coming home) | bed | 91 |
| 92 | Charles Darwin | Dig up | bone | 92 |
| 93 | Samuel Taylor Coleridge | Dream | opium | 93 |
| 94 | Godson Jesus | Polish (a boar-tooth necklace) | boar | 94 |
| 95 | Isaac Newton | Push (acceleration of gravity) | apple | 95 |
| 96 | J. Craig Venter | Clone (fuzzy peach bloom on hirsute face) | peach | 96 |
| 97 | Gandalf | Stop (the Balrog shall not pass) | book | 97 |
| 98 | Ferdinand the Bull | Smell (flowers) | beef | 98 |
| 99 | White Fang | Howl | puppy | 99 |
Notes:
In PAO, all 100 pairs of digits from 00 to 99 are associated with a Person, an Action and an Object. For example, 11 might correspond to a tattooed Queequeg hurling a harpoon. The object part of the image (a Tattoo) does not necessarily have to be the object of the action (Hurl), but it helps if the image is related so that remembering any part of it will help recall the other parts. For example, while the word tattoo points directly to number 11 according to the Major System ("1" = "T or D"), Queequeg as a Person doing anything else, or any action involving Hurling something, also refer to number 11. Therefore each of the 100 actions should be distinct enough not to overlap each other in meaning but still be capable of acting upon many objects. The Objects should be distinct from Persons ("Nemo" for number 23 was an exception because few object words were found having only "n" followed by "m").
To use this PAO system and make it personally useful, first it is necessary to obtain or construct and then memorize a personal library consisting of 100 persons, 100 unique actions and 100 objects of action. One way is to begin with a list of Objects corresponding to the Mnemonic Major System rules (see below). Another way might be to start with a list of Persons. In my case I started with Objects. For example, "onion" is an object which corresponds to number 22 because it contains two "n" consonants (vowels do not count). Then a Person and Action suggested by this object was chosen, in this case Job Weeping over an onion. After selecting 100 objects, next I selected Persons and Actions suggested by them. I had to make a lot of revisions to get Actions which did not overlap each other but which were still general enough to apply to many objects. Consider the handful of actions involving water: 23-Dory-Swim-Nemo, 31-Thor Heyerdahl-Float-moat, 69-Ulysses-Sail-ship, 72-Lewis & Clark-Paddle-canoe, 86-Old Man & the Sea-Surf-fish. These Actions are distinct enough not to be confused: Swim, Float, Sail, Paddle and Surf ("Surf" was changed from original "Row" because of possible confusion with "Paddle"). I had to replace a preliminary image of Aguirre, Wrath of God, drifting down the Amazon with a different image of Lewis & Clark, because Aguirre's raft was too similar to the Kon-Tiki raft even without Kon-Tiki's sail, and moreover Lewis and Clark used canoes, not rafts. I also wanted to avoid unpleasant persons. Most of my Persons were chosen for attractive or admirable qualities to invite them to reside in my memory palaces. I avoid actions of excessive violence or sex even at the cost of some mnemonic strength.
In theory, any sequence of six digits can be converted into a single composite image by combining the Person for the first pair, the Action for the second pair and the Object for the third pair. The vast number of possible combinations (100 * 100 * 100 = one million) produces memorable composites due to unexpected juxtapositions. Each composite image is deposited along a path threading a memory palace (Method of Loci). This in turn requires developing personal familiarity with a memory palace or a variety of memory palaces such as a set of rooms in one's home or a set of landmarks in the local neighborhood. Memory retrieval is accomplished by retracing the path taken previously, recalling the image of each composite deposited at each location and then converting them back to their corresponding numbers.
For the problem of odd-length numbers which do not break up nicely into pairs of digits, one solution is to consider them as overlapping pairs, for example 123 = 12 + 23. In my experience, after having perfected a satisfactory set of Actions which took a number of months, I find that combinations of Action + Object yield more dynamic, memorable images than Person + Object. When there is no person involved, that is for three-digit or four-digit numbers treated as Action + Object, sometimes it is convenient to replace the Action with an Adjective or an Adverb, since there is no confusion about the ordering of the numbers if the Object is always the last number pair. For an example of Adjectives or Past Participles functionally equivalent to Actions, consider these three-digit numbers treated as overlapping pairs: 023 = 02 + 23 = splash + Nemo = "splashing Nemo". 598 = 59 + 98 = Dance + Beef = "dancing bull". 835 = 83 + 35 = Laugh + Mule = "laughing mule". 942 = 94 + 42 = Polish + Rhino = "polished rhino".
As of 11/2011, I am practicing on translating six-digit numbers into composite images and back again. The development of the memory palace assignments is postponed for later. I recommend the site http://www.random.org/integers/ to obtain practice sets of integers. Select 400 integers, 10 columns per page, to get lists of 40 integers per column. When the paper is folded in half, this furnishes practice sets of 20 numbers. The creative challenge is to find a combination of Person-Action-Object which is somehow relevant to the Person, knowing something about the Person's character. For example, consider the number 511740 (PAO = Marie Curie - Back off - Rice). Knowing that Marie Curie was French reminds me of Marie Antoinette who supposedly said of the peasants "Let them eat cake" if they could not get bread to eat. So I imagine Marie Curie backing off from eating common white rice because she may have had a delicate stomach as a result of radioactive exposure in her lab. Practicing like this, imagining scenarios which do not exist in reality but which relate somehow to a store of knowledge of the world, may have a beneficial effect of exercising an aging mind, hopefully, like the reputed benefits of solving crossword puzzles or chess problems. When waiting for a bus or walking along a road bearing heavy traffic, it is fun to convert the license plate numbers into images as they quickly pass by.
Little flash cards cut in quarters from 3X5 index cards can help to memorize these lists of 100 items. The more sophisticated electronic flashcards by Anki (free download, see update note 4/29/2012 above) are also useful and may include images as part of the answer. In the beginnng I found it simpler to create separate paper index-card sets for Person-number, Action-number, and Object-number pairs and practice each of them separately. However I use a more integrated training format for the Anki electronic flash cards: an image of the Person is displayed on the front side and the three attributes of Number-Action-Object are listed on the back.
# Phonetic Table of the Mnemonic Major System, with optional colors
0 S s sibilant as in "z"ero Black
1 T, Th or D t or d = single stroke like 1 Red
2 N n = 2 vertical strokes Orange
3 M m = 3 vertical strokes Yellow
4 R fou"r" Brown, Beige, Magenta
5 L L = Roman 50 Silver *
6 J, Sh or Ch j =lower loop like 6 Gold *
7 K, hard C or G K contains two 7's sideways Green
8 F or V f = two loops like 8 Blue
9 P or B P = mirror image of 9 White
*The Magpie Song: "One for sorrow, two for joy, three for a girl, four for a boy,
five for silver, six for gold, seven for a secret that must never be told."