I could pickup the technique to help me in my day to day life. For very little investment in efforts it managed to drastically improve my life.
Context: I consider myself quite challenged when it comes to memorizing numbers.
The technique described in the book (and in this article) allowed me to remember details of a financial instrument which involves 32 numbers without any pattern. Whenever I have to use this instrument I have to input random 6 numbers out of those 32. Before I discovered this technique I had to pull out the hardcopy of the instrument every time for reference (it was painful - sometime it will be not in my possession, or it would be buried inside some cabinet etc.)
The technique that I use/adapted essentially is, I use mental map of a roadway which I’m intimately familiar with to place the 32 numbers on the various 32 landmark along the way (landmarks can be anything - a funny looking rock next to the road will also do. The key is one should be able to visualize it very clearly). So, whenever I need to retrieve numbers I mentally ’drive’ on the road and start checking out the landmarks. Example: I need to retrieve number corresponding to landmarks 5,9,15,20.. I start ‘driving’ reach landmark no. 5 and able to remember immediately this landmark is associated with number 29, then I move on and reach to next landmark, when I ‘reach’ that one I’m able to recollect that this landmark has number 89 associated with it, and so on…
Somewhere I read that it works so well because as a human species we have ability to remember geo spatial things much better than abstract things like numbers. I would guess that it has to do with our hunter-gatherer days when we were primarily dealing with spatial concepts; brain is hard wired to store those information much better than things like numbers.
Also for those who want a book that demonstrates the use of creating a memory palace, I would recommend The Memory Palace - Learn Anything and Everything. You'll just learn the 37 plays of Shakespeare wherein almost of the descriptions were funny.
I also listen to a free audiobook Memory: How to Develop, Train and Use It by William Walker Atkinson.
 - https://en.wikipedia.org/wiki/Harry_Lorayne
 - https://www.amazon.com/Memory-Palace-Anything-Everything-Sha...
 - https://librivox.org/memory-how-to-develop-train-and-use-it-...
Also highly recommended by Mr. Atkinson: The Power of Concentration (under his pen name Theron Q. Dumont) .
You construct words by mapping consonant sounds to numbers and using whatever vowels you need to construct words.
Other people learn gibberish sentences instead. They break down the number into groups of two, three, or four and use pre-memorized words for each group of words.
So to memorize the number "102457692" they might break it up into three groups: 102, 457, 692. Then they have a word memorized for "102" (ton) and a word for "457" (rolling), and "692" (cheapen). They memorize the number as `ton rolling cheapen`.
Words are easier to memorize than numbers, even if the words don't form proper sentences.
123 is always encoded as "tomb" in my phonetic system.
555 is always lilacs.
22 is always an onion.
When an image repeats, I place a mirror at that spot.
So 123-555-2222 becomes: a tomb, lilacs, an onion, and an mirror. I store them in a certain order with a story to keep them in order.
Not really. I phrased it that way ("driving down") for a simple explanation. I actually zip around at light speed on that road :-). After doing it for a while I can now 'jump' from landmark to landmark instantly.
> Do you write each number down, pause and recollect the next number, write it down, pause and recollect...
Yes. The moment I get a number I enter that in a text field (I'm actually using this to fill up a bank form for completing financial transactions). It does not matter if I'm in a noisy place or not, it does not need super focus or anything like that.