Léo Solé

Léo Solé — June 28, 2021

Secure software for exams

We created NumWorks in the hopes of designing an open and collaborative calculator. For this reason, we chose to be transparent and share our knowledge. This allowed users to suggest improvements.

A community grew around our calculator over the years and we have been lucky to work with teachers, students, developers and calculator enthusiasts alike. Members of our community have contributed to our calculator in many different ways. Our first users chose the colors of the marking on our keys. Also, teachers in our community chose which multiplication symbol would increase their students’ understanding of our calculator. Finally, contributors on GitHub improved our German software translation. Contributions from our community members are numerous and extremely valuable, and we are so grateful for you!

That brings us to today, where our desire to remain open is challenged by the reality of exam security. Due to this, we must now make changes to our software.

How to balance providing open software with the strict security rules of exams?

Calculators are not ordinary electronic devices: they are educational tools that are frequently used in the classroom and on exams. Therefore, we must make certain that all students can use their calculators on exams by adhering to rules created and imposed by testing officials.

We are now faced with a difficult question: how do we keep our software open and participatory when it is subject to strict rules that could lead to its ban?

What changes and what does not change

We have decided to stay true to our philosophy despite the restrictions we must now put in place. Beginning with version 16, the security measures introduced will not be reversible and will implement the following changes:

  • Official software. A copy of the official software is always available in the calculator’s memory. If custom software is installed on a calculator, you must press the reset button on the back of the calculator to restore the calculator to an official version. We encourage all users and examiners to press the reset button before an exam. This will ensure that you are using official NumWorks software.

  • Unofficial software. Unofficial software can no longer access certain hardware. This includes the LED that indicates the calculator is in exam mode. Therefore, it will no longer be possible to take an exam using a calculator with personalized software. In addition, when the calculator is powered on a message will appear stating that an unofficial software has been installed.

  • Software license change. There is only one change to the new software license. We no longer allow redistribution of the NumWorks calculator software. You can always submit requests and feedback on GitHub to implement changes to the official NumWorks software.

We realize this change presents a problem to users that wish to personalize their calculator software. We know that this is a significant constraint, so we have come up with a compromise.

Custom applications instead of custom software

Beginning with the release of version 16, it is now possible to install additional applications on your calculator. You can view a sample application here to learn how to develop your own. We believe this solution will allow users in our community to continue creating while also allowing us to adhere to exam guidelines.

The NumWorks official software will now permit the installation of unofficial applications. However, when additional applications are installed, restrictions will apply like the exam mode LED will be unavailable. If you wish to use the exam mode, your calculator will restart and the installed applications will be deleted.

We want to reassure every user that takes an exam with our calculator, but we also want to remain collaborative. We hope that these decisions will allow us to accomplish this goal. Of course, security features are not the only new additions to the calculator in version 16! We hope you have fun discovering all of our new features!

Léo Solé
Léo Solé — Product Manager

Léo is the mastermind behind the technology in the NumWorks graphing calculator. He joined our team as the Product Manager in March 2016. Léo has a Master's in Aerospace Engineering! One of his goals is to create a roadmap for the technical team. The team uses this roadmap to implement all his ideas. Léo's main goal is to create the best possible graphing calculator for math students. When not dreaming about the calculator of tomorrow, Léo indulges in his other passion: cinema!


During your visit to our site, NumWorks needs to install "cookies" or use other technologies to collect data about you in order to:

With the exception of Cookies essential to the operation of the site, NumWorks leaves you the choice: you can accept Cookies for audience measurement by clicking on the "Accept and continue" button, or refuse these Cookies by clicking on the "Continue without accepting" button or by continuing your browsing. You can update your choice at any time by clicking on the link "Manage my cookies" at the bottom of the page. For more information, please consult our cookies policy.