Talking about memorising numbers, one should definitely mention this well-known system which maps consonants to digits: https://en.wikipedia.org/wiki/Mnemonic_m

Talking about memorising numbers, one should definitely mention this well-known system which maps consonants to digits: https://en.wikipedia.org/wiki/Mnemonic_major_system https://en.wikipedia.org/wiki/Mnemonic_major_system With a system derived from that you can quite easily learn to memorise a shuffled pack of playing cards, by which I mean: someone shuffles the pack of 52 cards and deals them out in front of you, one card every couple of seconds. An hour later you are able to recite the sequence of cards forwards or backwards. (But you can't do random access! What you've done is associate each card with its neighbours, so you can step through them forwards or backwards, without necessarily knowing which direction is which.)