The Major system: how to remember numbers

§ 1Why numbers are hard and words are easy

Digits are abstract and look alike, so a string such as 4 7 3 2 9 1 gives memory little to hold. Words that name objects are concrete: you can picture them, place them and link them. Working memory holds only a few items at once (Cowan put the limit at about four chunks), but a chunk can be large if you have a code that packs several digits into one meaningful unit.

The power of such a code was shown by Ericsson, Chase and Faloon (1980). With more than 230 hours of practice and a coding scheme of his own, one student raised his digit span from 7 to 79 digits. The Major system is a ready-made code of this kind.

§ 2The code

Vowels and the sounds of w, h and y carry no value, so you can add them freely to build words. The idea of turning digits into letters goes back to the seventeenth century and the French mathematician Pierre Hérigone; the sound-based form used today was refined in the nineteenth century.

§ 3Three rules that prevent mistakes

• Sound, not spelling. Knife is 28 because the k is silent; comb is 73 because the b is silent; phone is 82 because ph sounds like f.
• A double letter heard once counts once. Kiss is 70, not 700.
• One letter can be two sounds. The x in fax is k plus s, so fax is 870.

Because the code is based on sounds, it can be adapted to any language: each language maps the same ten groups of sounds onto its own spelling. Avoid words with unclear sounds, such as ng and th in English, when you choose your list.

§ 4Build a 00–99 list

Most users fix one word for every number from 00 to 99 and learn it once. Short, concrete nouns work best. A few examples from a common English list:

You do not need someone else’s list. A word you choose yourself is often easier to recall, an instance of the generation effect: across 86 studies, Bertsch and colleagues (2007) found an average benefit of about d = 0.40 for producing material yourself. Check every word by saying it aloud.

§ 5How to memorize a number with it

1. Learn the ten sound groups until you can name the digit for any consonant at once.
2. Fix one word per number from 00 to 99, or start with 00–19 and add ten more at a time.
3. Split a long number into pairs: 473291 becomes 47, 32 and 91.
4. Turn each pair into its word: rock, moon, bat.
5. Link the words in a scene or put them on the places of a memory palace: a rock smashing into the moon, a bat flying out of the crater.
6. Recall by replaying the scene and turning each word back into digits.

For long numbers, put one or two words on each place of a memory palace. Competitors use larger systems such as PAO (person, action, object), which pack six digits into one scene, but a 00–99 word list is the usual foundation.

§ 6Limits

The Major system makes numbers memorable, not effortless. Encoding is slow at first and becomes fast only with practice, and without review the images fade like anything else. Use it where numbers matter to you: dates, codes, figures for a talk or an exam.

Questions and answers

Is the Major system hard to learn?

The ten sound groups can be learned in one sitting with the memory hooks above. Turning numbers into words quickly takes regular short practice, and a fixed 00–99 list speeds it up.

What is the difference between the Major system and PAO?

The Major system turns digits into words. PAO gives each two-digit number a person, an action and an object, and combines three numbers into one scene, so one image holds six digits. Many people build PAO on top of a Major list.

Does the Major system work in other languages?

Yes. The digit-to-sound code stays the same; only the spelling changes. Each language needs its own word list, chosen by pronunciation.

Can I use it for phone numbers and PIN codes?

Yes. Split the number into pairs, turn each pair into a word and link the words in a short scene. A four-digit PIN is just two words.