First video: Remembering and locating a chain of 20 decimals of Pi, within the first 25,000 and reciting the next 100 decimal. Second video: Making a triple sudoku, number + color, blindfolded.

First video: Remembering and locating a chain of 20 decimals of Pi, within the first 25,000 and reciting the next 100 decimal. Second video: Making a triple sudoku, number + color, blindfolded.

15 December, 2014 - 22:40
Joined: 3 years 7 months ago

Great videos! How long have you been training on pi?

15 December, 2014 - 22:59
Joined: 7 years 2 months ago

Incredible performance. I'm very interested in your triple sodoku. How did you do that?

14 January, 2015 - 19:13
r30's picture
Joined: 4 years 10 months ago

Notice that he takes a pause after telling each digit? That means he must be using single digit coded system (not XX or XXX), meaning he has 25000 images for Pi digits!. Suppose he uses method of loci to place the images, let's say he stores 3 images per locus (0-9 PAO), we get 25000/3 = 8333 loci to memorize. Now, he has to somehow enumerate the loci, let's say he assigns number to every 30th locus. That makes 25000/30 = 833 loci, and 734*3 + 90*2 + 9*1 = 2391 extra images to memorize. All in all we get 25000+8333+2391 ~= 36000 details to remember.

The time it would take?
If he memorizes on average 1 image in 8 seconds we get 8*36000 =288 000 s = 80h.
Let's say he reviews it 9 times before going to the show. Now he recalls an image in 4 seconds. We get 4*9*36000 = 1 296 000 s = 360h.
Together it makes 360 + 80 = 460h ~= 19 days. If he memorized 8h per day it would take him 57 days.

But a guy who can compose a triple sudoku in his mind surely has a faster system (not single digit) that I can't think of to memorize the digits of Pi.

9 November, 2015 - 03:36
Joined: 3 years 10 months ago

Josh, empecé a memorizar los decimales del número Pi en octubre de 2011. Trabajaba 2 ó 3 meses y me paraba otros 2 ó 3 meses. En enero de 2013 tenía memorizado los primeros 25,000 decimales. Sigo memorizando de forma intermitente. Actualmente tengo ya memorizados los primeros 70,000 ;-)

9 November, 2015 - 10:08
Joined: 3 years 6 months ago

Hi Paco, well done, great performance.

Since you mentioned π , I just saw here: that there is a new Pi WR this year (2015) at 70,000 digits by the Indian Rajveer Meena.

But I'm not sure if that's the official WR. Because the Pi World Ranking site
still lists the Chinese Lu Chao as the current WR holder
with 67890 digits (done in Nov.2005)


12 November, 2015 - 04:18
Joined: 3 years 10 months ago

Hi Nodas, muchas gracias por tus palabras y por la información sobre el nuevo record de Pi.
Veo que tendré que memorizar más decimales para batir el nuevo record de Rajveer Meena ;-)

12 November, 2015 - 07:43
Joined: 3 years 6 months ago

Hey Paco keep going buddy. I personally know another mental calculator and fellow competitor, Mr. Jan Van Koningsveld from Germany (and Netherlands), who is an official judge of the website. During the Mental Calculation World Cup in 2012 (Giessen Mathematikum) and in 2014 (Dresden), I witnessed some π - Pi record trials and attempts by other people (during the breaks when one can try for new records). But I did not try myself, because I was focused on the competition, so reciting Pi to some digits would be an extra interference and distraction. But I may make some attempt in the future. For me even 2000 or 5000 would be an fantastic achievement, let alone 10 or 20 thousand. But if Rajveer Meena's actual new WR of 70 thousand is correct and verified, then that is incredible feat indeed.
A day has 86400 seconds, so for a recital rate of 1 digit per second, probably he needs almost 20 hours just to recite it. The problem is that even if I ever knew a 100 thousand digits, I could never break the world record, because after being awake 20+ hours I'd feel very drowsy and probably make a mistake somewhere. I find it extremely superhuman to be focused on something for 20+ hours consecutively, without getting dizzy or distracted.

I also read that a Japanese has done 86+ thousand π digits, but it was not confirmed. I am not sure if he made mistakes in the recital or if there were not official judges, but the fact he even attempted 86 thousand digits, that means he had memorised all those, which is an fantastic achievement itself, despite not making an official record. Another unbelievable thing is that we human beings, can not even flawlessly memorise a bunch of 100 thousand digits correctly, whereas for digital disks that's only a file of size just 100 Kilobytes, not even a millionth of an external hard drive. Despite all mnemnonics and calculation efforts it seems that we humans as a species are very inefficient when it come to brute-force of number encoding and their respective images association and representation in hippocampus and neocortex brain areas. But at least, we have to keep active what we got and keep practicing memorization.

We know that we humans, are now much worse than computers in mind sports, but we still do memorization in order to keep the brain active.
A related 'machine vs. human' analogy: the ISS (Space Station) speed is around 8 km/s, a thousand times faster than the human running speed at 8 m/s (e.g. which corresponds to the WR of 800 meters of Track&Field/Athletics , around 100 seconds for 800 m). Nevertheless, even if we humans made rockets and supersonic airplanes, we still run for hobbie or champion sports to keep active. The same applies for mind or memory sports (pi included) or chess.
I think the main gain for us, from such a routine activity (like Pi memorization), is the transferable skill of potentially memorising any information one wants (up the human limits though), and then store it in long-term memory.

Also, unlike the WMC Memory category of 1-hour decimals, which are presented and get forgotten afterwards (e.g. by the next day),
the π-Pi is a specific number however, and goes further into long-term memory, much more than '1-hour decimal numbers', which has a human WR of 2660, by W.Feng ( '11) , still amazing, but less in size than most Pi records.

12 November, 2015 - 13:19
Joined: 4 years 4 months ago

Wow! Es increible saber que usted es del video! :D

Había visto el del sudoku anteriormente, es genial poder hacer eso, de ahí intenté hacerlo y lo logré :)
Ahora veo el del Pi, y también es genial, y poder saberse todos esos decimales, yo solo me sé los 30 primeros

Lo felicito :)

17 April, 2016 - 21:13
Joined: 7 years 2 months ago

i'm very curious to know what is the method to locate a chain of 20 decimals of Pi and reciting the next 100 decimal? Plz anyone advise?

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