The Mental Calculations World Championship (online) 2023 (hosted by the Mind Sports Olympiad as part of their Grand Prix) has just finished, and we have the winners!
Out of about 50 entrants, 20 qualified to this semi-final, and the top 8 were invited to the final, held on Monday 6th March 2023.
Daniel Timms (that’s me) wrote the questions for the final and semi-final, and I was in the Zoom calls with the participants. I was impressed as always with the high standard of competition, organization of everyone involved, and respect for the other participants. Congratulations to everyone who qualified, who did very well to qualify to these last two rounds!
Grand Final
The top 8 participants had the same set of 25 questions, shown in a Zoom call. They had between 20–60 seconds to answer each question, with some bonus points for the fastest answers. The competition was open to people of all ages, but in fact only under-18s qualified to the final.
The time limits and synchronous format make it a very high-pressure competition! See the semi-final video below for a simulation. See also the Mind Sports Olympiad official results page and a video of the entire event where you can also see how terrible my hair looks at 7am.
🥇 Kaloyan Geshev 🇧🇬 (243 points) is the overall winner. His top questions include:
- Expressing 18881 as a sum of squares. Kaloyan found the solution 130² + 44² + 6² + 3² in under 15 seconds!
- Searching through a list of past and future dates for those that fell on a different day of the week to the rest. Kaloyan found each of the three dates before anyone else.
Kaloyan—aged 12—is also last year’s gold medallist at the MSO (in London). He was awarded ‘Most Versatile Calculator’ at the 2022 Mental Calculation World Cup, and won the under-12s age category in the Junior Mental Calculation World Championship 2022 (JMCWC). He is a particular expert in exact cube roots and inexact square roots. He also enjoys cycling and making climatograms.
🥈 Aaryan Shukla 🇮🇳 (233 points), from Maharashtra state, wins the silver medal. He had a similar score to Kaloyan throughout the final. He was the fastest to solve:
- 135818 × 725284 = 98,506,622,312
- 29 × 97 × 62 = 174406
- estimating the cube root of 794 as 9.26
Aaryan—also aged 12—won the last online Mental Calculations World Championship in 2021 by a significant margin, He also collected the overall gold medal last year at the Mental Calculation World Cup in Germany. His favourite category of mental calculation is flash anzan (adding numbers that are presented on a screen in a rapid sequence), and also enjoys cricket and reading fiction books.
🥉 Vandan Nyati 🇮🇳 (166 points) wins the bronze medal. He regularly performs strongly in international competitions and today gets his first major medal, distinguishing himself in questions such as:
- Using Fermat’s method to factorize 8249 = 73 × 113
- Dividing fractions (3 5/32) ÷ (1 8/9) = 1 365/544
Vandan—aged 14—is particularly good at divisions. As well as mental calculation, he plays cricket and does photography. He trains with Trendz Abacus in Rajasthan, along with 6 other participants in the semi-final.
Andrej Zivanovic 🇷🇸 (129 points) was the youngest competitor in the final, at 11 years old. He improved from 8th place in the semi-final to make 4th place in the final, solving questions such as:
- What is the remainder when 28^76 is divided by 37? [Note: 28^76 is a 110-digit number!]
- Write 149623 as a sum of squares. One possible answer is 386² + 23² + 7² + 7²
Andrej is particularly good at calculating the day of the week for dates far in the past and future, as well as reading fantasy and science fiction books (which may also be set far in the past or future). He won silver in the under-12s age category at the JMCWC last year, only 5% behind Kaloyan.
Abhilakshya Arora 🇮🇳 (114 points) achieved 5th place in the world. He earned several bonus points for speed, including for:
- Finding the prime factorization of 435625, which is 5 × 5 × 5 × 5 × 17 × 41
- Multiplying fractions (7 11/18) × (5 4/7) to get 42 17/42
Abhilakshya came 3rd at MSO online 2021, and won the under-20s age category at the JMCWC 2022. His favourite mental maths categories include cube roots. When he’s not training his brain, he also enjoys playing sports.
Radhika Maheshwari 🇮🇳 (111 points) comes 6th, and she adds to her history of strong performances at the highest level in mental calculation, including bronze in the Junior Mental Calculation Online Championship in 2021. Her correct answers today included:
- Finding exact cube root of 600,357,185,856 in less than 20 seconds (the answer is 8436)
- Calculating the square root of 1132 to 4 decimal places (the answer is 33.6452)
As well as mental calculation, Radhika also likes to write and to travel, and she has visited Germany several times to compete in the JMCWC.
Aaryan Gupta 🇮🇳 (100 points) came 7th overall. Some highlights include:
- being fastest to solve 5/6 + 4/7 + 3/8 = 1 131/168
- getting the 3rd-highest score in the semi-final, with a perfect performance in the first 24 questions
Aaryan Gupta also trains with Radhika, Abhilakshya and Vandan, and won silver at the under-15s age category at JMCWC 2022 in Germany. He also plays sport when he is not training mental maths.
Kaede Kodachi 🇯🇵 (77 points) qualified from the semi-final despite that she had compete in the middle of the night. Some of the toughest questions she answered in the final were:
- Factorizing 8249 = 73 × 113 (by performing about 20 trial divisions in under 1 minute)
- Taking less than 20 seconds to find that the square root of 60,000,516 is 7746
Kaede is particularly experienced at divisions, and has competed online before, when she reached the top 4 the last time this competition was held, in August 2021. She also enjoys reading books and watching Hollywood movies.
Semi Final
The semi-final involved 20 participants, and was held on Sunday 26th February.
The table of results for all participants is at the bottom of this page. The Mind Sports Olympiad has published the full results here with a breakdown by question. 17 of the participants were from India, and all were under 18, except for Aditya Kumar, who is an adult (the top performers are typically very young and can beat top adults!)
Semi Final Video Sampler
After the 2021 event, I prepared a sample video so that you can go through the questions as if you were actually competing! Grab a pen and paper, and watch the video, which will explain the steps.
These questions are a sample of the 2021 questions—the 2023 event had more questions (25) but a similar level of difficulty. Good luck!
Further Reading
To find out more about competing in mental calculation, check out the following links:
- Information about all international competitions
- Various resources about learning mental calculation
- Article about preparing for the day of a competition
- Advanced calculations methods (including calendar, multiplication, roots and division)
There should be more opportunities to compete in mental calculation in 2023–2024, including at the Mind Sports Olympiad (L0ndon and online), the JMCWC (Germany, for under-20s), the Mental Calculation World Championship (Germany) and possibly more. Keep in touch with the organizers of each event for further information. I’ll also publish announcements here, by email and on the Facebook page.
This event was part of the Mind Sports Olympiad, which also hosts various mind games, such as Scrabble, memory sports, diving chess, and Settlers of Catan.
Semi Final Ranking of Scores
| Competitor | Score | Ranking |
| Aaryan Shukla | 143 | 1 |
| Kaloyan Geshev | 142 | 2 |
| Aaryan Gupta | 141 | 3 |
| Abhilakshya Arora | 132 | 4 |
| Radhika Maheshwari | 113 | 5 |
| Kaede Kodachi | 109 | 6 |
| Vandan Nyati | 108 | 7 |
| Andrej Zivanovic | 106 | 8 |
| Swanand Bhore | 91 | 9 |
| Garvita Raj | 88 | 10 |
| Deepak Nagar | 81 | 11 |
| Parth Garg | 78 | 12 |
| Hrishikesh Bunage | 53 | 13 |
| Harsh Nahata | 48 | 14 |
| Veer Sahas Bagi | 45 | 15 |
| Aaryan Mahesh Dalvi | 42 | 16 |
| Saksham Garg | 33 | 17 |
| Aditya Kumar | 32 | 18 |
| Trish Mathodia | 28 | 19 |
| Agamya Dadhich | 4 | 20 |