NOTE: page not yet translated



We have tweaked a bit the HTML output of the generator. It follows the (light, dark) theme you have chosen to use on the site. The table have stripped columns or rows.


Happy new year, everyone.

That's the time of year, we thank our donors that helped to pay the bill to let the site up.

This year, we thank Kevin, Matyáš, Jessica, Alexis, Anderson, Yeon, Malcolm, Michael, Maritta


We are transfering our domain name to a new registrar. This should be absolutely transparent to everyone... except if we did not deal with it correctly ;-)

Just expect a few hiccup in a week. We should be online fast even if something break.

Note: this will help decrease our domain name bill.


We have tweaked a bit the PDF templates to add a little more margins and padding to ease reading and writing on the pages


We have upgraded the site to use the new bootstrap 5.3 and refreshed the style of the site; nothing major, just minor changes here and there.

Please, keep donating to help us with the cost induced by the site. There is only 21€ for 2023 so far.


Happy new year, everyone.

We would like to thank our donors of 2022 for their donation, that helped keep the site alive:

Brandon, Christian, Christian (again), Daniela, Do, Jens, Malcolm, R.K., Stéphane, Steven, The Abacus Club.


Il y a une version française du site maintenant. Tout n'est pas encore traduit, toutefois.

There is now a french version of the site. You can choose your language in the menu.

If you want to translate the site in your preferred language, contact us. It will be best to gather a small team of 2 or 3 people to work on a translation. Because this is a tedious work, and it is hard to finish it alone.

Votre serviteur a fait seul la traduction française et est bien content d'avoir (presque) terminer.

We are looking for translators into portuguese (pt-br possibly) and spanish.


The forum has been moved from its subdomain to Some links on the the site still point to the old URL. They should be updated really soon.


And while we are at it, we found a way to disable the nagging UAC prompt when running mentalcalculation on Windows. It is just a matter of running the app as a normal user and not escalate privilege to administrator.

The 0.5.2 release contains the fix for this.


An issue was discovered (thanks to James) about a certificate error when downloading sounds on Windows in So here is a new release 0.5.1 to fix that.


As suggested by Christian, we have removed the "Show answers" button in interactive HTML document produced by the generator. This is to avoid "to be tempted" to look at the solutions.

It will come back soon, once we found a way, to transmit a secret to enable it


We have updated the HTML pages generated again, to include a PIN code to be used, if you want to see the solutions.


With a little delay, let's just celebrate the 10th anniversary of our site with a little timelapse; thanks to


Happy New Year 2022 for every one. We take this opportunity to also thank the donnors of 2021. Thank Adam, Mark-Anthony, Darren, Ismael, Erwin, Charles, and Evelyne for their donations.


We are currently experiencing problem to deliver emails to any 'yahoo' addresses. We don't have a solution yet, but we're trying to slow down the rate at which we send subscriptions after 00:10 UTC to avoid this issue.

And if you didn't receive any subscriptions today, this is because of a bug we introduced (it is now fixed). Sorry.

[Update] This seems to be fixed for now.


We don't use any more Google Drive to host our download files. They are directly served from our domain from


The forum has finally been upgraded and is back online. It is now hosted on the subdomain You will need to register to post.

Using the same email address and username than used in the previous forum is possible (but you will need to register anyway).


We have switched back to using the Google TTS API in mentalcalculation.html. We just hope it will be fine this time.


After a few downtime and hiccups, we have moved the hosting of the site from the clouds of Google App Engine, to Sorry for the inconvenience.

You may encouter some bugs we have not squashed; so please feel free to contact us to let us know. After all this, we just hope, you won't have to.

If you interested in using please use this link to allow us to get some discount back for the referral.


Because of an unexpected cost arising while using the Google TTS API, we are reverting to use the Microsoft TTS API in mentalcalculation.html page.


We have added a training page to help master the basics of the soroban. This is best used with the basics page, where you will find a link to each setof exercises on this new page.


The mentalcalculation HTML page is now using a Google TTS API (instead of the previous Microsoft one).

This change should not be visible too most users; but you might hear the difference 😋. If you encouter a bug, don't hesitate to let us know by using the contact form.

Also, the version 0.5 of the PyQt software Mental Calculation has been released. The main change is the ability to choose the language of the speech synthesis from the settings dialog. It is also using the same Google TTS API.


Happy holidays!

The mentalcalculation page has been updated to the new design. The settings are in a modal dialog now. The voice language is automatically chosen from your locale, if specified.

One can click on the header (with index) of a table in a generated HTML. This will highlight the column in addition/substraction table. Or the multiplication/division.

And yes, we use our home-made header image now.


You can now specify the number of digit (up to 3) for the anzan worksheet in XLS format.

We have changed a bit the numbers generated for the division to get a null reminder for higher kyu. Thanks to Thomas T.


We currently have an issue delivering subscription emails to some addresses. Our ESP (Email Solution Provider) has some of its servers blacklisted, and some email services (like Outlook/Hotmail/MSN) are simply dropping our emails.

We apologize for the inconvience. We are working to fix that.


After a few weeks of intermittent efforts, we have upgraded the app running this site to python 3 and to a new web framework.

With 117 files changed, 4504 insertions(+), 5363 deletions(-), this significant change will only affect the core and underlying engine of the site and will not be visible to most users.

Appart from a few cosmetic changes, another visible change is that some page have been renamed:

  • /mentalcalculation-only.html ==> /mentalcalculation.html?fullscreen=1
  • /soroban-only.html ==> /soroban.html
  • /ws/XXXXXX ==> /ws/serve/XXXXX

However, if a bug has evaded our hunt, you can contact us with the message form, using the link in the footer.

The forum is not finished yet, and will come back as soon as possible.


Downloads are now hosted on Google Drive; and all links starting with are redirections.


[Obsolete] is now an alias for


Generated HTML output files are now styled with bootstrap.


[Obsolete] All downloads (exe, zip, pdf, etc ... but not exam pdfs) are now hosted on and delivered to you by


We have added a limited set of exercises based on grades from This was to add requested very easy kyu levels. We include 10th kyu to 13th kyu. We may eventually add the other level templates based on's one. My thanks to Sherwin.


Added a visual clue about the selected column when using the keyboard on the full screen virtual soroban


A bug fix release for mentalcalculation: 0.4.1


We have removed the mention to worksheet.html but the page is still there for the few people that might be interrested. It was more an exercise with no real usefulness. Instead the stats page is put forward.


We have fixed a small bug in mentalcalculation-only.html page, and as requested by Valentin, the settings are saved in localStorage now. They will be restored automatically when you go back to the page. We have also added an history feature too. And finally, you can choose to get no TTS sound. Choose No sound in the Voice Language menu.


First of all, happy new year everyone.

We have implemented a feature request from pi_over_two ... from 2011. Better late than never.You can now have the approximate level of difficulty of an exercise set given its number of fingering.

The fingering count is printed inside brackets [] after the index of the set or with a number of stars from 0 to 3. If you have chosen to get the solution printed either at the end, or on another page, the count is printed there.

You will notice that some set deviate from the mean fingering count by having a low or high count.

The fingering is approximated using a simple algorithm consisting of comparing digit change in each step of an operation. This closely matches the japanese fingering on the soroban.


We are now accepting donation in bitcoins.


Update of mentalcalculation to version 0.4. There is no more the need for espeak to get speech synthesis as we use now a microsoft API for TTS. But this means, you need a working Internet connection to play sound with mentalcalculation.


The site is now served also via https. And you are slightly forced to use it as we have setup a redirect to https. This is the recommended practice on the internet nowadays aynway.


Update mentalcalculation to to fix a bug when clicking OK in settings dialog that make crash the software.


A new dedicated page at practicing anzan with spoken number. Compatible with mobile where you are urged to go full screen (using the link in the menu bar).


Redesign with a switch to Bootstrap. The site is now responsive and finally mobile and tablet friendly.


Remove the google ads


After 6 years, fall down to the siren call of adsense! Complain to if you dislike to see ads here.

2013-01-05 version of mentalcalculation fixes a problem with the file

2013-01-05 version of mentalcalculation fixes a problem with turkish minus sound


A problem that broke anzan/excel generator during one week is fixed. Did anyone notice ?


Minor update for mental calculation, now at


Some rare users of the pdf generator may have been surprised to get a nyan cat in the top right corner of their pdf. It started with a test for a logo (more on that later) and ended up as an easter egg. ;-)

the nyan cat

Don't hammer the generator to get one! It's randomly generated and no more than once per day.

2012-02-27 version of mental calculation is out. It increases the time before showing answer in "hands-free" mode. And don't fail if phonon is not present.

Warning: It seems there is a bug in phonon 4.6.0 on Linux; it breaks mental calculation. Try to use the 4.5.1 version of phonon or else try to use the vlc backend of phonon (but it is not that better).


Fix virtual soroban that was not displaying in IE6 and IE7. It was just a matter of a comma...


Add a turkish translation to worksheets. Fix display of utf8 character in pdf for some locale and configuration.

2011-12-06 version of mental calculation just changes the README/LISEZMOI to be more explicit about the option of Windows explorer that needs to be changed to be able to see hidden files/directories and to access the configuration file.


0.3.5 version of mental calculation is released; you can use F11 to switch to full screen. Font size is auto-adjusted with the size of the window. It is available in several new languages now: czech, spanish, italian; french was already available.


Add 2 screencasts about mental calculation.


Another version: of mental calculation with other options now available: changing the font.


Another version: of mental calculation with other options now available: changing the colors of background and font and use a sound after each number. Look at the README.


Version of mental calculation is out just to add a minimize button at the main window.


Version of mental calculation is out just to change various maximum values in the settings dialog.


One can now use the virtual soroban on an interactive HTML worksheet.


Add a 9th kyu level for Moritomo aka. Official Abacus Association template.

Add an interactive html option to the generator to enter manually the solutions and check their correctness.


Switch from excanvas to flashcanvas to support IE6 and IE7 for the virtual soroban!


IE9 users on Windows 7 can pin the site/tab in their taskbar. And a new page with only the virtual soroban.


Some small changes, here and there, that you might notice... or not. The most notable one is that you can get 25 anzan worksheets at once now.


Version 0.3.4 of mental calculation is out:

  • There is now a new mode called "continuous" that does not ask for an answer each time, but gives you the answer anyway to let you check if you found the correct result. It will continue automatically to display a new sequence.
  • It has also a 'Replay' button which replaces the complicated use of the 'Shift' key.
  • And there is a full-screen mode now.


Follow us on Twitter @sorobanexam


Version 0.3.3 of mental calculation is out. It fixes a bug about the way to replay by using <shift>+<Return> and adds the long-awaited possibility to force espeak to pronounce numbers one digit at a time.


Add the possibility to see the steps of a custom operation on the virtual soroban.


Add a timeout option to the virtual soroban to speed up or slow down the play of tutorials.


Did you notice the Flattr button on the top right of the generator page ? You can now Flattr the website/generator !


Introduce a forum because there were too many comments (previously managed with the help of disqus).


We have a new domain name: You could update your bookmark to use


0.3.2 of mental calculation is out. It allows replaying a sequence. It would be helpful for beginners or for the ones trying a higher level of difficulty. You can't score twice when replaying a sequence you gave a good answer.

How to replay a sequence:

  • If you have checked your answer already (by clicking 'Check' button), just press 'Shift' and the 'Start' button will become a 'Replay' button. Just click it, STILL holding the shift key!
  • If you have not checked for an answer, just press the 'Tab' key to put the focus on the 'Start' button. This way, when you will press the 'Shift' key, the 'Start' button will become a 'Replay' button too. In this case, it does not work without pressing 'Tab'

2010-12-29 of mental calculation is out to fix some bugs with espeak language and command when specified from the .ini file.


That's embarrassing: a new release of mental calculation, version, to fix a bug where one always a get negative number.

And yet another release,, to remove the sign of the first number if using subtraction and rename negative numbers to subtraction in settings as suggested by pi_over_two.


Update mental calculation software to

  • Enhance behavior regarding sound
  • Fix a bug with random number


Modify slightly the generator layout and redesign the subscription submit form.

Add the possibility to view the worksheets created by the generator during the last 3 days. Is this useful ?


A new stylesheet for the site! Using a new header image. The image is a modified version of the one found on I emailed them but never got a response. So I assumed it's ok.


Anzan xls generator is configurable now. You can choose with or without negative numbers, solutions and how many numbers in each addition

If you see a negative level for an anzan subscription, this can be dechipered as follow: negative sign means there will have negative numbers hence subtraction, the absolute value of the level is the number of numbers in each addition.


Use tabs in generator page. Move anzan generator to generator.html page.


Fix a bug when no locale has been detected.

Allow the bulk retrieval of 25 copies at once.


Subscription to receive an Anzan XLS worksheet is now possible too.


Subscription system to receive exercises by email regularly.


Add a menu to pick a locale from the list of the autodetected ones.

Provide translated/localized PDF/HTML for the following locales:

  • french
  • german
  • greek
  • hungarian
  • italian
  • polish
  • portuguese
  • russian
  • spanish

Please use the forum to flag any error you may found: the translation comes from Google Translation.


Use the examples from the 2nd book of Takeshi Kojima Advanced Abacus: Japanese Theory and Practice as a template.


There are 3 alternate stylesheets for the HTML output. Change the stylesheet from the menu of your browser.


New template based on the document (or here) provided by Gilbertus Albans from A.F.S.A. They are the grades from the Osaka Abacus Association.


Autodetect locale to properly format the numbers.


There is a new output format called Basic HTML which is, in fact, a properly aligned text version (and might replace the Plain Text version).