Monday, July 17, 2006

Mnemonic Major Systems

I discovered two things when I tried using the net to brush up on mnemonic major systems (aka phonetic number systems). (If you have no idea what they are read the article before continuing!) Firstly, the only encoding from digits to sounds I've seen online so far is the one published by Harry Lorayne. Secondly, it turned out I didn't need any brushing up at all. The mapping I learnt many years ago was so easy to remember that, not only can I still recall it, but the memory is so strong I cannot use Lorayne's system without confusion.

I came across the major system I use in a book by Jean Hugard. I argue that it is more natural and easier to learn. There were only a few rules to remember:

1,2,3 correspond to the consonants l,n,m respectively. This is easy to remember since the letters require 1,2, and 3 strokes to write. If you happen to know the British sign language alphabet, observe that you place 1, 2 or 3 fingers on the other hand's palm when signing l, n and m respectively.

Some mappings are based on the way you pronounce digits in English. 4 is r (think “fourrr”), 5 is f or v (think “five”). 0 is s or z (think “zero”).

Then there are the digits that look like letters. 6 is b or p, 7 is t, th or d. 9 is k or g. With sufficiently bad handwriting (or fonts), 6 and b are indistinguishable, as are 9 and g (or q, which in English is always pronounced starting with a k or g sound, and always as a k sound in several European languages). 7 and T are also similar.

The only rule I never liked much was the one for 8 (which is not a problem since being the odd one out makes it easy to remember!): “Eight” sounds like “aitch”, which hopefully helps you remember that the sh, ch (and j) sounds correspond to 8.

Digit Consonant(s) Reason
1 l strokes
2 n strokes
3 m strokes
4 r sound
5 f, v sound
6 b, p shape
7 d, t, th shape
8 ch, j, sh special
9 k, g, q shape
0 s, z sound

I also mostly prefer the mapping from playing cards to words as presented by Hugard. Although I dislike the aces been treated specially and agree with Lorayne assigning the names of the suits to the jacks, I believe thinking KH as a groom and QH as a bride for example is easier to learn.

However, there is at least one practical benefit to Lorayne's system. By Benford's law, it is more likely that a number one wishes to memorize begins with a 1, and it is easier to think of a word starting with d, t or th than to think of one starting with l.