Memoriad 2024 took place 06–10 November in the UAE (official website), following the previous events in 2008, 2012 and 2016. It is an international competition of memory and mental calculation. Each competitor could choose a selection of events from the 12 events available.
Although the event was announced publicly only 2 months beforehand, 121 competitors participated in mental calculation events, representing Algeria, Australia, Bulgaria, Colombia, Cuba, Germany, India, Japan, Mexico, Mongolia, the Netherlands, Pakistan, Qatar, South Korea, Spain, Turkiye, Turkmenistan, Ukraine, the UAE and the UK. Almost 30 more competitors joined only the memory events.
[Note: due to my personal schedule, I wasn’t at this event and this results article was published five weeks after! Thanks to various calculation friends for their updates and for permission to use their photos in this article.]
Additions of 10-digit Numbers
Competitors solved ten tasks, each being an addition of ten 10-digit numbers. That’s a total of 1000 numbers to add up! Over 100 participants entered the addition event.
The winner was Jeonghee Lee from South Korea (based in the USA) who completed all additions in 122 seconds total. She also won this event 8 years ago. She is also one of most experienced mental calculators, having started over 50 years ago! In contrast, the silver and bronze medals were won by 13-year-old mental calculators.
1st: 🇰🇷 Jeonghee Lee (122.36 seconds)
2nd: 🇮🇳 Parmar Priyansh Kiritbhai (140.68 seconds)
3rd: 🇮🇳 Tambe Vighnesh Vijay (182.72 seconds)
Special mention also to 🇮🇳 Swanand Bhore who was the fastest overall (115.26 seconds) but with a minor error. He recently held the world record for additions. 🇮🇳 Siddhi Mukesh Jain was also very fast, with 9/10 correct in 165.41 seconds.
Multiplications of 8-digit Numbers
Competitors solved ten tasks, each being a multiplication of two 8-digit numbers, such as 84736251 × 43214321. Here is the most popular method for multiplying large numbers in your head.
Previous world record holders Jeonghee Lee and Freddis Reyes achieved 3rd and 2nd places, while Shashank Jain had a convincing victory, averaging less than 22 seconds per question with perfect accuracy! In total, 57 participants entered the multiplication event.
1st: 🇮🇳 Shashank Jain (218.47 seconds)
2nd: 🇨🇺 Freddis Reyes (229.75 seconds)
3rd: 🇰🇷 Jeonghee Lee (239.27 seconds)
Special mention also to 🇮🇳 Pawar Riddhi Ganesh who was the fastest overall (185.30 seconds) but with a minor error. 🇮🇳 Swanand Bhore was also very fast, with 9/10 correct in 233.78 seconds.
Square Roots of 6-digit Numbers
Competitors calculated ten square roots, each to 8 significant figures. For example, √612543 = 782.65126 (8 s.f.) Most mental calculators use the mental square roots method (or a variation of it).
Only 5 competitors had a perfect score: 🇩🇪 Dirk Ewers; 🇮🇳 Bhusare Siddhi Dnyaneshwar; 🇦🇪 Akash Rupela; 🇧🇬 Kaloyan Geshev and 🇮🇳 Shashank Jain. In total, 38 participants solved square roots.
1st: 🇮🇳 Shashank Jain (40.82 seconds)
2nd: 🇧🇬 Kaloyan Geshev (79.37 seconds)
3rd: 🇦🇪 Akash Rupela (239.55 seconds)
Special mentions to 🇮🇳 Das Anshuman, 🇧🇬 Georgi Georgiev and 🇨🇺 Freddis Reyes who also solved everything in under 230 seconds with 9/10 tasks correct.
Division by a 5-digit Number
Competitors calculated ten divisions, each of a 10-digit number that was a multiple of a 5-digit divisor, with a 5-digit answer. Most competitors use a version of this mental division algorithm to find the most significant digits, and some memorized shortcuts to find the last digits. There were 27 participants involved here, and 3 familiar names took the top places:
1st: 🇧🇬 Kaloyan Geshev (71.65 seconds)
2nd: 🇰🇷 Jeonghee Lee (77.77 seconds)
3rd: 🇮🇳 Shashank Jain (82.72 seconds)
Calendar Dates
Competitors had 60 seconds to determine the day of the week of many dates in the range 1600–2099. You can learn the fastest method for calculating calendar dates here. Out of 57 participants, the fastest two people solved all 125 dates in less than the 60 seconds available—more than 2 calculations per second!
1st: 🇮🇳 Jay Baldiya Jain (125 dates in 51.24 seconds)
2nd: 🇮🇳 Siddhi Mukesh Jain (125 dates in 57.37 seconds)
3rd: 🇧🇬 Kaloyan Geshev (108 dates in 60.00 seconds)
Flash Anzan Marathon
In this event, series of numbers are flashed on the computer screen, and participants had to add them up. This starts with 1- or 2-digit numbers displayed slowly, and eventually 3- or 4-digit numbers are displayed for only a fraction of a second each. 66 participants were involved here.
2016’s winner 🇰🇷 Jeonghee Lee won again at age 61, while 4th places was taken by 9-year-old 🇹🇲 Mekan Nurgeldiyev and 10th place was taken by 7-year-old 🇮🇳 Riyansh Patil!
1st: 🇰🇷 Jeonghee Lee (57136.55 points)
2nd: 🇮🇳 Siddhi Mukesh Jain (53244.89 points)
3rd: 🇮🇳 Swanand Bhore (48978 points)
Special mention to 🇹🇲 Turkmenistan, whose team achieved 8 of the top 16 places.
Alongside mental calculation, there were six memory events. Some mental calculators also competed in some of these alongside mnemonists. Overall, these events were dominated by an extremely well-prepared group from 🇲🇳 Mongolia—well done to them!
The most powerful technique for most of these challenges is the method of loci (memory palace).
Numbers Marathon
In this event, participants were presented with a long sequence of digits (e.g. 477037623…) and had 15 minutes to memorize as much as possible.
1st: 🇲🇳 Uuriintsolmon Enkhjargal (1168 digits)
2nd: 🇲🇳 Munkhshur Narmandakh (1124 digits)
3rd: 🇲🇳 Naranzul Otgon-Ulaan (940 digits)
In fact, the top 9 places were taken by Mongolia! The top participant from another country was 🇮🇳 Nitesh Moksh Jain, with 372 digits.
Spoken Numbers
In this event, numbers are spoken aloud by computer software at a rate of one digit per second. Competitors need to memorize as many digits as possible.
1st: 🇲🇳 Oyun-Erdene Tsengelbayar (175 digits)
2nd: 🇲🇳 Enkhshur Narmandakh (164 digits)
3rd: 🇲🇳 Nomin-Erdene Tsengelbayar (162 digits)
Flash Numbers
In this event, numbers are presented one-by-one at a rate of one digit per second. Competitors need to memorize as many digits as possible.
1st: 🇲🇳 Nomin-Erdene Tsengelbayar (312 digits)
2nd: 🇲🇳 Naranzul Otgon-Ulaan (246 digits)
3rd: 🇲🇳 Myanganbayar Gantulga (234 digits)
In fact, the top 8 places were taken by Mongolia! The top participant from another country was 🇮🇳 Vishvaa Rajakumar, with 100 digits.
Binary Digits
In this event, participants were presented with a long sequence of binary digits (e.g. 011011110…) and had 5 minutes to memorize as much as possible.
1st: 🇲🇳 Uuriintsolmon Enkhjargal (1599 digits)
2nd: 🇲🇳 Oyun-Erdene Tsengelbayar (1382 digits)
3rd: 🇲🇳 Naranzul Otgon-Ulaan (1353 digits)
In fact, the top 8 places were taken by Mongolia! The top participant from another country was 🇩🇿 Walid Henni, with 330 digits.
Speed Cards
In this event, participants had to memorize the order of a regular 52-card deck of playing cards, as quickly as possible. The cards were presented using computer software.
1st: 🇲🇳 Munkhshur Narmandakh (19.47 seconds)
2nd: 🇲🇳 Oyun-Erdene Tsengelbayar (20.62 seconds)
3rd: 🇲🇳 Nomin-Erdene Tsengelbayar (22.05 seconds)
Special mention also to the other participants who memorized everything in less than 30 seconds: 🇮🇳 Vishvaa Rajakumar (23.89 seconds) and 🇲🇳 Naranzul Otgon-Ulaan (24.70 seconds).
Number–Shape Recognition
In this event, 3-digit numbers are associated with abstract shapes, such as a red rectangle. Participants must recall which shape is associated with each number.
1st: 🇲🇳 Munkhshur Narmandakh (269 correct)
2nd: 🇲🇳 Uuriintsolmon Enkhjargal (259 correct)
3rd: 🇲🇳 Enkhshur Narmandakh (257 correct)
Full results: although they are currently not navigable from the official websites, you can find the full official results here, including the ages, countries and exact times for each performance.
New World Records
After winning the square roots event with a time of 40.82 seconds for ten tasks, Shashank Jain then beat the world record three times, and it currently stands at 27.3 seconds!!
After winning the division event, with a time of 71.65 seconds for ten tasks, Kaloyan Geshev set a new world record of 29.6 seconds!! The large difference between the top competitors’ speed in the competition (70–80 seconds) and in record attempts (30–40 seconds) is due to the need to be extremely careful to avoid errors during the competition.
Congratulations to both new record-holders!
Get Involved in Competitive Mental Calculation and Memory
Would you be interested in competing in this event in the future? Here are some ways you can get started:
- Learn more about international competitions in mental calculation (and subscribe below for announcements). The next Memoriad competition is planned for Singapore in 2028.
- Read more about Memoriad on their official website and the official website for the UAE competition.
- To practise for Memoriad competitions (and for the Mental Calculation World Cup), you can use the official Memoriad software.
- Links to the individual techniques are provided throughout this article. Here is a larger list of advanced mental calculation techniques.
See you in Singapore for Memoriad 2028 (if not before!)