Step-by-step plan to take part in our latest Honorary Mental Math Challenge

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Important update concerning our Honorary Mental Math Challenge:

Our Honorary Mental Math Challenge is now officially over. Thanks and congratulations to everyone who participated! If you’re curious, you can click here to see everyone’s results.

Some of the info on this page is now outdated, but it doesn’t mean that you can’t still use it. I explain how in those few paragraphs taken from the home page of this website. I will copy-paste them here until I can find the time to adjust the presentation and all the little details:

The latest editions of our Honorary Memory Challenge and our Honorary Mental Math Challenge are now officially over. It’s unfortunately too late for you to be included in the scoreboards. However, if you missed the deadline, or if you want to attempt to do better than you previously did, it will always be possible for you to download the latest challenges and test yourself. The latest editions of our Honorary Memory Challenge and our Honorary Mental Math Challenge will always remain accessible online, and so will our memory and mental math training tools and sample disciplines. So if at some point in the future you want to try something and post your results, you’re very welcome to do so as a comment at the bottom of the honorary results page, as a post in this Facebook group or anywhere else you prefer.

Although they’re meant to accessible to people of all skill levels, those challenges certainly aren’t easy. It’s a little bit like trying to run an intellectual half-marathon. It can be exhausting. It can be (slightly) humiliating when you don’t do as well as you thought you would. But it’s a great way to force yourself to practice a bit more and to see what you can manage to accomplish. That’s why I’m (Francis Blondin) personally hoping to informally try both challenges again at some point in 2021.


The CMSA Honorary Mental Math Challenge is on until March 15!

The previously announced deadline has been extended. You can check this page, if you’re not sure about how this “honorary challenge” is supposed to work, but otherwise you can just scroll down, download your first document and start calculating whenever you’re ready.

Before you start:

  • If you’re unfamiliar with them, first make sure to learn about the different rules and events here
  • If you want to practice in advance, you can use some of the sample disciplines on this page.
  • You can click here if you want to learn more about how it’s possible to become much, much faster with mental calculations.
  • Do you want to answer everything directly on your computer or do you want to print out all the challenges in advance? If you want to print them all in advance, you can scroll down this page, download and print everything you’ll need now if you want. Important note: we added way too many pages and too many problems to each document, you almost certainly don’t need to print them all. We’ll tell you in advance how many problems appear on each page so that you can decide how many pages you might need to print. Documents are often 5 pages long just in case, but almost everyone will only need the first 1 or 2 pages.
  • If you want you can simply do one challenge once a while during your lunch break when you have time and e-mail us after you’re done. If you want to be more hardcore about the whole thing, you can plan in advance where and when you will be tested and do everything in one day, as if you had been competing in a real championship. If you go for that option, ideally I suggest you block out at least 4 hours in total for the big day, to make sure you have enough time for breaks and correction and so on.

For every single document, you will find 2 different versions and 3 different formats. You will find a version with only the questions and a version with both the questions and the answers. Obviously, make sure that you don’t accidentally use the documents with all the answers when it’s time to test yourself.

You can choose to use either .pdf, .doc or the .xlsx format. The .pdf documents should appear exactly the same no matter what computer or software you’re using. But because I used a lesser-known clone of Excell and Microsoft Word to design all the different challenges, it’s possible that the formatting of .doc and the .xlsx versions won’t appear on your screen exactly as I intended. It will probably be fine, but you might want to check first.

  • .pdf documents are read-only. They’re perfect for printing, but you can’t write directly on them from your computer. You could however choose to just write down your answers on a random sheet of paper or another open document.
  • .doc documents should work like Microsoft word documents. Normally you should be able to open them and write on them without any problem, but I can’t guarantee it 100%.
  • .slsx are like Excell documents. You should also be able to open them and answer directly on them, but I can’t guarantee it 100%.

Just to be clear, we provide many different versions of each document to make sure that everyone will find something that works for them. Just choose whichever format you prefer and ignore all the others. If you aren’t sure which one you should use, perhaps you could make a quick test or two before you officially start your attempt?

Friendly reminder:

  • If you’re taking part in the Advanced section, you have to calculate everything mentally before writing your answers. Your points won’t be considered valid if you also write down your calculations.
  • If you’re taking part in the Regular section, you face all the same problems as participants in the Advanced section, but you’re allowed to write down all your calculations. Writing down your calculations will of course be simpler if you’re printing and using pen and paper. If that’s not an option, you can do like me and write one sub-result on the first line after the problem before writing the full result on the second line. (For reasons we’ll explain below, you shouldn’t write anything on the third line)
  • If you’re taking part in the Beginner section, the problems you will face will be simpler. And you can of course write down all your calculations. Make sure to click the highlighted correct link to access the right documents.



Ready to start?

Ok so today is the day! I hope you’re feeling great and I hope you slept well the night before.

Some annoying last few points:

  • DON’T SKIP ANY PROBLEM! For every challenge, you have 5 minutes to try to solve as many problems as you can, starting with the very first. The scoring system will penalize you if you try to skip ahead to the easier-looking problems.
  • If you want to preserve all your energy for problem-solving, you can choose to wait until you’re done with everything before correcting your sheets.

How to note down your results:

For each event and each attempt, please note your attempted score (how many problems you gave an answer for) and how many good answers you got. For the best result you manage to achieve, also note down your final score including penalties. For divisions for example, maybe you answered 15 problems and got 12 right during your first attempt and you then answered 16 problems and got 13 right during your second attempt. In that case, here’s how you would note down your results: Attempt 1: 12/15. Attempt 2: 13/16. Final score: 11.5

In the example above, you lost half a point for the three mistakes you made. The way you will calculate your final score will vary from one challenge to the next. Don’t worry, we will reexplain what you need to know each time.

If you aren’t printing and you’re answering everything directly on your computer:

You should know that every .xlsx and every .doc document include some not always visible gridlines, some empty boxes where you can write your answers and some other boxes where the correct answers to each problem are written in white (and therefore invisible to you). You can make the gridlines visible or invisible by changing the options in the program you’re using. And you can make the correct answers visible by selecting everything and before changing the text color to black or to some other color. That means you can choose to first write down your own answers and then, when the 5 minutes are up, make all the correct answers appear next to yours. Using this method can considerably speed up the corrections process. If you’re not sure how to do this, this page explains everything in more detail. That’s true for all the main events and all the optional events. The image below shows you where those answers are hidden for different events:

Be careful to note down your answers either immediately to the right of each problem or, when possible, immediately underneath. It’s better to avoid writing in the boxes where the hidden answers happen to be.

Ok that’s more than enough rambling for now, let’s start your first challenge.


First challenge – Additions – 5-minute – Two attempts

[If you’re taking part in the Beginner section, please refer to this page for all the documents and instructions you will need.]

You should know this already but just in case: The pdf documents are perfect for printing. Use either the .xlsx or the .doc documents if you’re answering questions directly on your computer. Again use those instructions if you want to speed up the correction process. If you aren’t sure which type of document you should use, please check the more detailed instructions already written above in the “About the different types of documents” section.

Each additions document has 5 pages with 30 additions per page. Most people will have more than enough with just the first page. Some of the fastest participants will get to the second page. Very few or none will need more than that. If you’re printing, don’t print more than what you might need.

First attempt:

Second Attempt:

For each attempt remember to note not just the number of good answers you had but also the number of problems you attempted. Your final score will simply be the number of good answers you managed to get with your best attempt. Additions is the only challenge where mistakes aren’t penalized. The results you will send us should look something like this: Attempt 1: 8/10, Attempt 2: 9/11, Final score: 9


Second challenge – Multiplications – 5-minute – Two attempts

[If you’re taking part in the Beginner section, please refer to this page for all the documents and instructions you will need.]

[Please refer to this page if, like some advanced competitors, you would rather read your multiplications horizontally rather than vertically]

Each multiplications document has 5 pages with 64 multiplications per page. Most people will have more than enough with just the first page. Some of the fastest participants will get to the second page. Very few or none will need more than that. If you’re printing, don’t print more than what you might need.

First attempt:

Second attempt:

For multiplications, for divisions and for most of the optional challenges, your final score will be the number of good answers you got minus half a point for every mistake*. If you got 9 good answers and 5 bad answers, your final score will be 6.5 (9 minus half a point for each mistake). The results you will send us should look something like this: Attempt 1: 9/14, Attempt 2: 7/14, Final score: 6.5

* For every challenge except additions, if you choose to skip some problems, every missing answer will be considered a mistake and penalized accordingly. Of course no penalty will be given for unanswered questions past the last question that was answered.


Third challenge – Divisions – 5-minute – Two attempts

[If you’re taking part in the Beginner section, please refer to this page for all the documents and instructions you will need.]

Each document has 5 pages with 49 divisions per page. Most people will have more than enough with just the first page. Some of the fastest participants will get to the second page. Very few or none will need more than that. If you’re printing, don’t print more than what you might need.

For divisions, when necessary, you need to write a comma or a dot and the correct following 2 decimals. For those 2 decimals past the comma, we’ll accept either the straight non-rounded up or down answer, or when applicable the correctly rounded up or down answer. For example, the complete answer to 149/7 is 21.28571428571… We only want you to write 2 decimals past the dot, so 21.28 would be an acceptable answer and 21.29 (correctly rounded up) would be another acceptable answer. However, 21.27 wouldn’t be considered acceptable because in that case, rounding down wouldn’t make sense. For 155 divided by 7, the more complete result gives us 22.142857… In this case, rounding does not change anything and 22.14 is the only acceptable answer. If the answers provided in the documents below include 3 decimals and not 2, that’s only to help for those cases where rounding up or down might make sense.

First attempt:

Second attempt:

You will calculate your final score the same way you did for multiplications. 1 point for each good answer that you managed during your best attempt. Half a point penalty for each mistake.



That’s all you needed to do if you aren’t interested in any of the optional challenges below! Thanks for your participation! Please send your results to cmsa@canadianmindsports.com before March 1st at the latest. Use a pseudonym or just tell us if you don’t want your name to be published.

For the maniacs, we have no less than 5 other optional challenges and one “special event” that you might want to try. Everything you might want to know about those optional challenges is explained below:



Important notes:

  • For this honorary challenge and for all future in-person official championship, optional challenges are only presented because they can be fun and because we like to see new records being established or broken. Try them if you enjoy them, ignore them if you don’t. They are all judged separately. None of the results from the optional challenge have any influence whatsoever on the final ranking of a championship.
  • For all the optional challenges, the main scoreboard will be for those who didn’t write down their calculations before arriving at their answers. A second scoreboard will be for those where not everything was calculated mentally and some calculations were written down. If you choose to write down your calculations for some events, please tell us so when you’ll be sending your results.
  • As long as you make your intentions clear to us so that we can compile the results accordingly, you can choose to try some optional challenges while writing down your calculations and try some other optional challenges while calculating everything in your head.
  • Just like we’ve done so far, we provide a .pdf, .xlsx and .doc version of each document. And for each a version with the answers hidden and a version with the answers already visible. Just like before, you can use the same trick to speed up the correction process and avoid having to use any of the “Answers” documents.

Special event: Unpredictable Calculations5-minute – One or two attempts

Our first optional challenge is called “Unpredictable Calculations”. For all kinds of reasons, it operates under different rules than all the others, hence the “special event” designation. It’s inspired by one event faced by the participants of the Des chiffres et des lettres TV show. The problems you will see might look like this one: ((((( 32 x 13) – 46) / 5) + 17) x 4).

  • The exact format will be unpredictable, but they will only include some combination of additions, subtractions, multiplications and divisions.
  • The problems presented can always be solved by simply proceeding from left to right. All the parenthesis are only there to make it clear that you don’t need to bother with any of the rules about the order of operations. As you probably know, those rules state that all the multiplications and divisions are supposed to be done before all the additions and substractions. So 12 – 2 x 5 = 2 and not 50. With parenthesis (12 – 2) x 5 = 50 and not 2. For all the problems you will see in this challenge, you can choose to just mentally ignore the presence of all those parentheses and simply always calculate everything from left to right.
  • There are 2 different documents with 2 pages each and 20 problems per page. So 80 problems in total. The first document includes pages 1 and 2. The second document includes pages 3 and 4. For regular human beings who obviously won’t be able to solve more than 40 problems in 5 minutes, you can choose to use pages 1 and 2 as your first attempt and pages 3 and 4 as your second attempt.
  • If you’re some kind of alien and you want to attempt more than 40 problems in 5 minutes, make sure in advance to print or open both the document for pages 1 and 2 and the document for pages 3 and 4. If you choose to proceed this way, you will only be able to attempt this special event once.

Pages 1 and 2:

Pages 3 and 4:

One point for each correct answer. Half a point penalty for each mistake.

Thanks to Marc Larocque for all his work designing this special event!


Important note about the other 5 optional events:

  • We’ve tried to simultaneously allow some participants to attempt some optional challenges more than once while also limiting the amount of time needed to get through everything. Here’s the solution we came up with: You’re allowed a maximum of 5 attempts in total for all optional events, and you can choose to distribute those 5 attempts however you prefer! The one or two attempts you may have done already with the “Unpredictable Calculation” special event don’t count. So you could for example choose to attempt advanced multiplications three times and calendar calculations twice while skipping all the other optional events. Or you could try everything once. Or skip everything. Important note: – Three attempts is the maximum for any single optional challenge. – The one-minute and five-minute versions of calendar calculations count as just one attempt. So if you decide to use three of your five attempts on this one, you would be able to try the one-minute and five-minute formats three times each. – When you attempt the same optional event more than once, only your best result is counted at the end. – You have to decide in advance how you plan to use your 5 attempts. You can’t change your mind depending on your results! – Of course since this isn’t an official in-person championship, there’s nothing stopping you from trying everything three times over the course of several days. It’s of course completely cool if that’s what you want to do, but please make sure to distinguish between your “official” 5 attempts and your “just for fun” attempts when you’ll be reporting your results.


Optional challenge: Advanced Multiplications5-minute

[Please refer to this page if, like some advanced competitors, you would rather read your multiplications horizontally rather than vertically]

Multiplications of a 3-digit number by another 3-digit number. So 872 multiplied by 643 would be a possible example. As many as you can in 5 minutes. 1 point for each correct answer. Half a point penalty for each wrong or missing answer.

First possible attempt:

Second possible attempt:

Third possible attempt:



Optional challenge: Squaring – 5-minute

Squaring as many increasingly large numbers as you can. As many as you can in 5 minutes. First set of 15 problems will be 2-digit (63² for example). Those first few problems will probably be more than enough for most participants. For those who manage to get through all the 2-digit numbers, the next series of 15 problems will be 3-digit (352² for example). All the rest will be 4-digit problems like 6507². 2 points for each 2-digit numbers. 3 points for each 3-digit numbers. 5 points for each 4-digit numbers. Half a point penalty for each wrong or missing answer.

First possible attempt:

Second possible attempt:

Third possible attempt:



Optional challenge: Square Roots – 5-minute

Calculate the square roots of 6-digit numbers. As many as you can in 5 minutes. 1 point for the first correct digit. 2 points for the second. 3 points for the third. 4 points for the fourth. 5 points for the fifth. 6 points for the sixth. 7 points for the seventh. 8 points for the eight. So up to 36 points for a completely correct answer. Less for a partially correct answer. Half a point penalty for a completely wrong or missing answer.

First possible attempt:

Second possible attempt:

Third possible attempt:



Optional challenge: Calendar Calculations – 1-minute and 5-minute

Calculate the day of the week for any date from the year 1600 to 2099. You will have one 1-minute attempt and one 5-minute attempt. 1 point for each correct answer. Half a point penalty for each wrong or missing answer. To save time you can choose to answer using the numbers 1 to 7 instead of writing down the words “Monday”, “Tuesday” and so on. Depending on your preferences, you can decide in advance whether 1 is Monday or Sunday or Saturday.

1-minute – First possible attempt:

5-minute – First possible attempt:

1-minute – Second possible attempt:

5-minute – Second possible attempt:

1-minute – Third possible attempt:

5-minute – Third possible attempt:


Optional challenge: Insane Multiplications – 5-minute

[Please refer to this page if, like some advanced competitors, you would rather read your multiplications horizontally rather than vertically]

Multiplications of an eight-digit number by another eight-digit number. So something like 79,960,546 multiplied by 25,349,034. As many as you can in 5 minutes. 1 point for each correct answer. Half a point penalty for each wrong or missing answer.

First possible attempt:

Second possible attempt:

Third possible attempt:


That’s all!

Uselessly repeating myself again:

  • Please send your results to cmsa@canadianmindsports.com before March 15 at the latest. Also tell us if you took part in the Advanced, Regular or Beginner section. Use a pseudonym or just tell us if you don’t want your name to be published.
  • The all the results we’ve received will be published soon after March 15. Don’t hesitate if there are any comments (“I messed up this particular attempt because…”) you’d like to see being published along with your results. Just write “Comments: …” to make it clear that what you’re about to say can be published.
  • Cheaters will be caught and tortured by agents of the CMSA secret police.
  • Thanks again for your participation! You rock.