Click here for some CMSA sample disciplines and training tools.
The Honorary Mental Math Challenge is on!
For the countless legions of mental math fanatics out there, and for people who might want to try something new, we’re planning another free and unofficial online event. Just like our Honorary Memory Challenge, the Honorary Mental Math Challenge will be unofficial and self-regulated. Participants will be tested on their ability to solve as many additions, multiplications and divisions as possible during a series of brief 5-minute exercises. Most adults and students are fully capable of solving all those problems, but it will be impossible to answer them all correctly during the very limited time available. For the highly motivated, some new additionnal challenges will also be presented.
After too many long unexpected delays, the CMSA Honorary Mental Math Challenge is finally ready.
The previously announced deadline has been extended. You will be able to download the different challenges, test yourself and send us your results at any time of your choosing from now until March 15.
As always, casual hobbyists and complete beginners are just as welcome as experts to participate.
- Location: Anywhere you happen to be in the Universe
- Date: Anytime you want from now until March. 15, 2021.
- Cost: Nothing
- Rewards: Nothing (except eternal admiration by all current and future generations)
- Skills requirement: You need to be the legitimate owner of a human brain.
How will it work?
Any day of your choice from now until March 15, you will simply come to this page, download all the challenges and test yourself wherever and whenever will be most convenient for you. You will then send us your results. We’ll later publish a pretty scoreboard with all the results we’ve received. If you want, you can also send us some comments (“I messed up the divisions because the dog kept bothering me…”) for us to publish along with all the results.
As we’ve said, the Honorary Mental Math Challenge will be unofficial and self-regulated. You will need to self-regulate everything related to timing and scoring*. Overall it will be mostly just a game and a way for some of us to motivate ourselves to start training more regularly again. There won’t be any titles or rewards or anything real at stake. If we have very good reasons to think some results aren’t legit, we might refuse to publish them or add a small cautionary note next to their scores. Somehow, we don’t think that this will be necessary.
Some new improvements to the CMSA mental math format
As you may have noticed from the poster above, we’re introducing a few improvements to the CMSA mental math format. If you’re already familiar with the format that we’ve used in the past, rest assured that nothing has to change from your point of view. The main 3 challenges that everyone is judged on will remain the same. We’ve only added some new options that you can choose to use or ignore.
- First change: a new section for beginners. Simpler problems for young people and/or people for whom mental math can be difficult.
- Second change: many more optional challenges. Only for those who might enjoy them. Everything you might want to know about those will be explained at the bottom of this page.
Scroll down this page for more details and explanations on those changes.
Congratulations to Hua Wei Chan for his victory at the 2019 National Mental Math Championship and for his 2 new national mental math records!
The 2019 National Mental Math Championship was held Saturday November 23 in Montreal. Click here for the highlights and the full results.
Thanks to everyone who participated in one way or another!
And if you’re curious, here are the results of the 2018 National Mental Math Championship that was held the year before and won by Jean Béland.
Updated CMSA mental math events and rules
This is the format we will use for the ongoing unofficial online honorary challenge and also for future in-person official events. Competitors will be tested on their ability to solve as many additions, multiplications and divisions as possible during a series of brief 5-minute exercises. Most adults and students are fully capable of solving all those problems, but it will be impossible to answer them all correctly during the very limited time available.
Our events are open to people of all ages and all skill levels. No matter how good or how bad you are at mental calculations, one of our three sections should be well adapted to your skill level.
- The Beginner section: With easier problems, and the possibility to write down all your calculations.
- The Regular section: Same problems as the Advanced section, but you’re allowed to write down all your calculations.
- The Advanced section: You have to calculate everything mentally before writing your answers. Your points won’t be counted if you write down your calculations.
The three main challenges: additions, multiplications and divisions
Although many more optional challenges will later be presented, only the first three challenges will determine the final ranking. For each of those three challenges, competitors will have two 5-minute long attempts separated by a short break. In each case, only the best of those two results will be counted.
- For participants in the Regular and Advanced sections, the first challenge will be additions of ten 2-digit numbers like 36+44+78+14+97+32+28+81+96+25. Participants in the Beginner section will instead have to add ten 1-digit numbers like 3+4+7+1+9+3+2+8+9+2.
- For participants in the Regular and Advanced sections, the second challenge will be multiplications of two 2-digit numbers like 47 multiplied by 82. Participants in the Beginner section will instead have to multiply one 2-digit number by one 1-digit numbers like 43 multiplied by 6.
- For participants in the Regular and Advanced sections, the third and last mandatory challenge will be divisions of a 3-digit number by a 1-digit number between 2 and 9. So 732 divided by 5 would be a possible example. When necessary, you will need to write a dot or a comma and the next correct 2 digits. Participants in the Beginner section will also have to divide a 3-digit number by a 1-digit number, except that the problems presented will always have a round answer. That means that we might ask something like 730 divided by 5 (answer: 146) or 678 divided by 6 (answer: 113), but we won’t ask 732 divided by 5 (answer: 146.4) or any other question where you would need to add a dot and a coma and some additional digits to your answer.
- As mentionned previously, other optional challenges will be presented for those who might enjoy them. Whether or not you choose to try them won’t influence the final ranking of a championship. The nature and rules of those optional challenges will be explained at the bottom of this page.
During an in-person event, by default most participants you will be shown 2 pages with 30 additions each, 2 pages with 64 multiplications each and 2 pages with 49 divisions each. Those extremely rare participants who might be able to solve more than this can write to us in advance to request more pages. For the currently ongoing online honorary challenge, the documents provided will be long enough for partipants of any conceivable skill levels.
Click here for some sample disciplines and training tools.
Click here to learn more about how to become crazy fast with mental calculations
Overall scoring rules
- For additions we simply add up the number of good answers. All the questions presented are about equally difficult.
- For multiplications and divisions, we also add up the number of good answers, but half a point will be subtracted for every wrong or missing answer. This is to avoid giving an incentive to skip the most apparently difficult questions. No penalty will be given for unanswered questions past the last question that was answered.
- 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.
DON’T SKIP ANY PROBLEM! Except for additions where all problems are about equally difficult, all missing answers will be penalized.
All the numbers used will have been generated randomly by specially designed Excel documents. You can find those documents in the sample disciplines and training tools section.
Final ranking calculations
*For the upcoming honorary challenge, you don’t have to worry about that part. We’ll take care compiling everything and coming up with an overall result for everyone.
As we’ve said only the first three challenges will determine the final ranking. The rest is mostly just for fun and bragging rights. For each of those three official challenges, each contestant will be awarded a score that can range from 0 to 100. Those three scores will be added at the end and whoever get the most points wins.
In each challenge the person who obtained the very best score will automatically have a score of 100. Other contestants will have their score calculated by taking the number of good answers they obtained and by dividing that number by the number of good answers obtained by the best competitor and by multiplying the result by 100. So if the best performance in the division challenge was 50 good answers and you obtained 40 good answers, your official score for that challenge will be 80 (40 divided by 50 and multiplied by 100).
We’ll present three different scoreboards for competitors in the Beginner, Regular and Advanced sections. Non-Canadian citizens can’t become the official “Canadian Mental Math Champion”, but they are more than welcome to compete in any section and show everyone who’s boss.
Optional challenges for the highly motivated
As we’ve already said: 5 additional challenges will be offered, but they will be completely optional and they will each be judged separately. None of those optional challenges will influence the final ranking of the event. You don’t have to practice them if you don’t want to. We’re only offering them because they can be fun and because we want to see some new national records being established.
The 5 optional challenges will the following:
- Advanced multiplications: 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. Here’s one possible method you can learn to use to do this faster. And here are some more complete explanations for the same method.
- Squaring: 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. Note that there are relatively simple techniques you can learn that makes squaring much easier and faster than other forms of multiplications. It’s one of the first “impressive tricks” that beginner mental calculator can learn to show off to their friends. Doesn’t mean you’ll instantly become good without practice!
- Square roots: Calculate the square roots of 6-digit numbers. As many as you can in 5 minutes. 1 point for the first correct digit of each answer. 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. Note that once you become familiar with the techniques involved, calculating the square roots of a 6-digit numbers isn’t necessarily more difficult than doing the same thing for a much smaller number.
- Calendar calculations: Can you quickly tell me what day of the week was October 23, 1743? Jean Béland and many others can correctly calculate the correct answer for dozens of similar problems in just one minute! It may seem borderly impossible, but it’s actually something that with practice you can learn to do very quickly in your head. How? Here’s one simple way. And if you have a system for memorizing numbers, there’s a much quicker way explained in French here and in English here. To save time you can answer using the numbers 1 to 7 instead of writing down the words “Monday”, “Tuesday” and so on. We can ask 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.
- Insane multiplications: 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. Yep…
- No “beginner versions” of those optional challenges will be offered.
- 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. Difficult problems are much less difficult when you don’t have to do them all in your head! Whether or not you signed up for the Advanced or the Regular section, 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.
- 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! 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!
And sometimes, we may add one more “special event”
At the very last minute, we decided to add one “special event” to our honorary challenge. It’s called “Unpredictable Calculations”. It’s inspired by one event faced by the participants of the Des chiffres et des lettres TV show. For all kinds of reasons, it operates under different rules than all the others, hence the “special event” designation.
- This “special event” is one more optional part of our ongoing “honorary challeng”. We don’t currently know whether or not we’ll add this to any of our future in-person championship.
- You can eigher choose to try it or choose to ignore it. It doesn’t count for the “maximum of 5 attempts in total” rule for all the other optional event.
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 always include six different numbers along with 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.
5 minutes in total. One point for each correct answer. Half a point penalty for each mistake.