Savant School: How to Memorize 10,000 Numbers and More


The spectrum of human memory potential: Daniel “Brainman” Tammet beats blackjack and Japanese schoolchildren become human calculators.

Numbers, or digit strings, are considered by many mnemonists and cognitive scientists to be the most difficult data to memorize. If numbers are both abstract and difficult, how did Hideaki Tomoyori of Japan memorize PI to more than 10,000 places? How did my classmate in Tokyo also multiply four-digit numbers in seconds?

The answer is proper encoding, or translation of the abstract to the concrete. Hideaki used what I’ll teach you here, whereas my classmate used a phantom abacus like in the above video.

The average person can only hold seven or fewer numbers in their working memory at any given time, using vocal repetition as an aid. Using proper encoding, trained subjects can memorize all of the area codes in the United States within a 24-hour period… By encoding abstract data first as letters, then as nouns, one can accurately store and recall hundreds of items (images) both forwards and backwards.

This introduction to encoding will provide an overview of the consonant system mnemonic, which encodes numbers as consonants of the English language. In this system of encoding, vowels (a, e, i, o, u) have no value, nor do w, h, or y. Numbers are converted to consonants, which are then converted to nouns and images. Bear with me — the examples make this simple to use.

Here are the encoding pairs that Tomoyori used to recall 10,000 numbers without error. Numbers are encoded as indicated below, and suggestions for remembering the pairings are provided in parentheses:

1 = t (also th) or d (single downstroke)
2 = n (two downstrokes)
3 = m (three downstrokes)
4 = r (the last letter of “four” is “r”)
5 = L (you have five fingers on your Left hand)
6 = j, ch, soft g, sh (“J” is a near mirror-image of “6”) (Ex: Jelly, CHips, garaGe, SHoe)
7 = k, hard g, hard c (“7″ side-by-side with a mirror image form a sideways “K”) (Ex: Kite, Goat, Cat)
8 = f, v, ph (“8″ is similar to the lower-case cursive “f”) (Ex: Flame, Vest, graPH)
9 = p or b (9 is a mirror-image of “P”)
0 = z, s, soft c (0 signifies “zero”) (Ex: Zipper, Scarf, iCe)

Using the above conversion table, 8209 could equal “fan” (82) and “soap” (02), thus a fan made of soap. If you can then place one such composite image at 20 preselected locations (loci), you will memorize 80 numbers with ease. Numbers are converted to words by the phonetics (sounds), and spelling is unimportant. Thus: 8762 = FKSHN = fikshun = fiction (vowels possess no value). Use whichever vowels you want.

Likewise, repeated letters are represented by a single number unless two separate sounds are made: 3230 = MNMS = Minnie Mouse (“nn” represents the single 2).

The second step is to take each image, made from 2-6 numbers, and place them in a sequence. The loci method uses preselected and familiar locations:

1. Choose a familiar route marked intermittently by outstanding features. Horizontal sequences are easiest to use: streets, hallways, room perimeters, etc.. Using the path from your bed to the shoe rack as an example, the following locations could serve as placeholders for your composite images: bed, bedroom door, staircase, kitchen table, shoe rack.

2. Associate your composite images, in appropriate order, with the predetermined locations. To memorize the number (905) 811-3710, you could follow this sequence:

a. PAISLEY (905 = PSL) sheets on your bed
b. A huge PHOTO (81 = FT) of yourself plastered on your bedroom door
c. Princess DI (1 = D) sitting on your staircase
d. A huge MUG (37 = MG) on the kitchen table
e. TIES (10 = TS) where shoes should be in the shoe rack.

By mentally tracing your loci route, you produce (905) 811-3710. And guess what happens if you trace your route backwards, taking into account the order of letters? 0173-118 (509). This combination of encoding methods automatically permits you to recall digit strings both forwards and backwards!

Encoding, and improved abstract recall, can be used to learn 500 foreign vocabulary words in a single 12-hour session, increase IQ testing results by 20-30 points, or memorize all of the ticker symbols on the NYSE.

Increase your recall capacity by 500% and you can effectively quintuple your lifetime learning capacity. Learn to efficiently encode the abstract and the results can be superhuman.

Posted on: September 5, 2007.

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62 comments on “Savant School: How to Memorize 10,000 Numbers and More

      • You can also try my iPhone/Android App “The 4 Most Powerful Memory Techniques” which will give you further memory techniques. Do let me know how it goes. Thanks.


  1. Just started subscribing, Tim. Great stuff. I really appreciate your perspective, as well as all the sweet tips.

    Unfortunately my day job requires a tie each day. Thanks to you, though, I’m now a windsor knot guy. Peace.


  2. Can one apply this mnemonic technique to perhaps memorizing an entire deck of cards, removing one, then determing which one has been removed by going through the entire deck?


  3. Killer post Tim. Coincidentally I’ve spent the past week digging into this searching for methods to boost my learning retention and memory chops. So far the best book I’ve come across has been titled Mind Performance Hacks by Ron Hale-Evans. The whole concept of mind palaces and the various number encoding systems out there is fascinating.


  4. Has anyone else read Daniel Tammet’s book, “Born on a Blue Day”? Daniel has a form of autism/Asperger’s syndrome, and his book is an interesting taste of how that kind of mind approaches the world. It’s odd, but worth reading, especially if anyone you know is somewhere on the autism/Asperger’s spectrum.


  5. As usual an interesting post Tim. The technique you have used seems to have originated from Harry Lorayne’s book by the name ‘How to have a super power memory’ which I remember reading as a kid. This technique you have described is called the Peg technique.

    To remember a list of thousands of objects in sequence you can use another technique called the link technique, where you make ridiculous associations between the sequence of objects. Eg: Phone, Book, Comb, Fish…
    1. Imagine yourself talking into a huge Book instead of a phone.
    2. Imagine yourself studying for an exam reading a massive comb
    3. You are fishing at a lake, and you pull out combs instead of fish
    and so on…


    Hi Mo,

    This “peg” technique — often referred to as the “loci” technique — actually originated in Greece, from what I’ve read, where Socratic-era orators would use it to remember speech points, as written notes were forbidden. Harry is a smart man, though, to be sure.




  6. Hey Tim,

    You could be right about the greek origins. Btw, using these techniques to remember speech points is an excellent application of this method. Thanks for mentioning that. I wonder if world leaders use these techniques in their seemingly fluent and long speeches.



  7. so 500 foreign vocab words in 12 hours (and all the other amazing stats) what would your error rate be when tested? 85%? and retention period? THANKS DAN for the url… any other good (as in simple/easy) sites to pick this up?


    Hi Victory,

    If followed with a repeat session of about 1 hour on the slower items the following day, I’ve generally seen an 80-90% retention rate after 24 hours. The forgetting curve is typical Ebbinghaus after that.

    For the VA questions, I’d recommend you hit the resources I recommend in 4HWW, especially, but you can also try, which has good tools. Just post your criteria on each marketplace you choose.




  8. Derren Brown has a book called Tricks of the Mind that includes some cool memory tricks plus some magic tricks as well. But you’ll have to order it from the UK Amazon to get a hold of it.


  9. Someone once asked Einstein how many feet were in a mile. “I have no idea,” he said. “Why should I fill my mind with useless facts that can be found in any reference book?”

    The mind is better used for *thinking* than for storing endless facts. Yes, being able to remember Pi to 10,000 places is interesting….

    …Wouldn’t it be far more efficient to use the ancient reference method “pencil and paper” and then go spend the rest of your time doing something *fun*? ;)


    • Memory is a key component to thinking. For example, if you spend some mental effort memorizing numbers, memorizing numbers becomes easier and easier. You are developing a new capacity in your brain which actually expands thinking rather than impeding it. The brain does not get “filled up,” it grows.


  10. I recently talked to a competitive digit-memorizer (mnemonist?), and according to him, the standard technique among memorizers is something a bit more complicated. Basically, you associate a character, an action, and an object with each two-digit number. That lets you chunk each six-digit number into an image: Maybe 425661 is Bruce Lee (42) sweet-talking (56) a pile of rubies (61). You can then use the method of loci as Tim described. (Interestingly, this leads to odd errors with perceptual explanations — if Bruce Lee is 42 and Jackie Chan is 98, you might insert 98 where you were supposed to have 42 if you didn’t cement the image in your mind firmly enough.)

    The limitation of this system relative to Tim’s/Tomoyori’s is the up-front time commitment. A ten-number system probably takes much less time to master than a 100-number system, especially where each number maps to three different things. However, it’s much more determinate — instead of making choices about how to shoehorn the number-sounds into words, you’ve got a fixed image for every location — and more efficient (6 digits per image instead of 1-3 in Tim’s example).

    In theory, you don’t have to limit yourself to two-digit numbers; obviously a three-digit system would be more efficient, since each image would be worth nine digits instead of six, and so on. But apparently almost no competitors have had success with three-digit systems — I’m guessing it’s just too hard to come up with 1000 people, actions, and objects that are so distinct that you won’t confuse them with one another. However, I think there’s at least one guy who’s used a three-digit system extremely successfully.

    Sorry to be so hand-wavy about all this — I’ve gotten it only from conversation, so I don’t have any references for any of it. But the guy I was talking to did definitely memorize 120 decimal digits in 2 minutes, and describe the images and the route he used, so I’m confident that he knows what he was talking about.


  11. Nice hack Tim! Speaking of hacking things, do you happen to have a copy of your audiobook “How I Beat the Ivy League” available? I would love to hear that as I’m planning to go to business school. Or perhaps you can make a post about it?

    Thanks and keep up the good work!


  12. Well described. Two systems: numbers=letters (and vice versa) item locations. Both work wonders but I find ‘item locations’ more practical. Lecturers in ancient Greece studied art of memory, to dramatic effect. In the day, it was common to see students wandering slowly, deliberately around Athenian buildings–memorizing features as mental reference for “storing” objects of recall. I recommend storing objects in a mental representation of your clearest “house” memory. For example, I know my childhood home in extreme detail so that’s my virtual database. When I want to remember a series of objects, I mentally drop off each object in myriad room locations. Each position has a special, emotional meaning to which I may associate with the object I’m leaving there. When I want to recall all the objects, it is quite easy: I walk around the house in a standard path and collect all the objects from the standard positions. It’s tedious mental work, but completely doable to memorize the entire menu at a restaurant this way. To add more layers of information, I am free to add the numbers trick. Net, if I drop off a Caesar salad at the front door to my house, and the salad costs $6.31, I think J M N which I’m free to translate as “Cumin,” so I dump an absurd amount of Cumin on a Roman looking doorman who is lunching on salad. These pictures are difficult to forget, hence the detail one can remember is remarkable.


  13. The loci method isn’t so great because you’re limited by how many items you can remember in your house/whatever to begin with.

    The peg system that mbm was referring to in an earlier comment is actually the link system where you link one item to another until the end of your list.

    As I understand it, the peg system is great unless your peg system isn’t based on phonetic mnemonics. For instance if you just randomly pick words to associate with the numbers 1-10 in order to memorize a separate list of ten items, you’ll do fine but what if you have to remember 100 items or more? How are you going to remember what number stood for what item? That’s where the phonetic mnemonic system comes in … and you covered it in your post, sort of.

    Each number has a sound, so if you ever forget any number, you can sound it out with the phonetics and that will remind you of the object associated with that number. This is unlike a random list of objects associated with numbers.

    Example: 1 can’t be ball because it has the ‘t’ sound. But one can be tie! The sound of the number (phonetic mnemonic) will remind you of the associated word!

    Making phonetic mnemonics from 1-100 even 1-1000 etc, or using someone else’s pre-made list will prepare you to use the link method (and drop the loci method) with a great advantage over the loci guys.

    For instance, you could memorize PI to as many digits as you’d like by just linking your image for the first three numbers to your image for the next three. Then linking your image for those three numbers to the next, etc.

    Of course, as mjw has said, learning those initial 1000 or 100 numbers might be sort of a [short] time commitment, but it could be worth it for some people.

    If you can memorize the first 100 peg words, or whatever you’d like to call them, the next 900 will be a breeze! How? All you do is take your image for the number 1 and set it on fire to mean 101 or put it in ice to mean 201 or smother it in jelly to mean 301, etc.

    The system is pretty easily expandable. Lets say you don’t even want to go that far. Lets say you just want to memorize 100 items. Ok, just memorize the first 10. Your image for 1 might be “t”ie, and your image for 2 might be “n”oah. Don’t link these, because you want 100 separate items. Now what would the image for 12 be? It could be a frozen noah! And 11 could be a frozen tie? 22 could be a burning noah, and 21 could be a burning tie! Etc.

    Anyways, I hope I helped spread some … memory love.