Information Collection And Use

If you are not a member, you have full access to all our pages. We do not need and do not ask for your name, email or any other personal information.

If you are a member, we use your email and name for login purposes and to allow you to save exercise scores to a database. Score information is only available to you or – if you are a student and are part of a group – to your teacher or teachers. As a member, you agree to the collection and use of information by this policy.

In the case of schools, we can create accounts using fake emails and names.

We do not share your email. We only use your email as a username to login and to keep track of your scores.

We do not collect or have access to credit card numbers. MyCommerce (a Digital River company) or PayPal process credit cards.

Log Data

We use Google Analytics to collect, monitor and analyze information such as your browser type, browser version, the pages that you visit, the time and date of your visit, the time spent on those pages and other statistics. See how Google uses this information. If you are a member, we do not include Google Analytics code after you login.

We store your preferences when using our exercises and some pages using HTML5 local storage. This information is only used to restore your options the next time you run an exercise.

If you write to us using our online forms, we collect your browser and OS version, your IP address and the address of the page that originated the email. This information will help us to pinpoint problems you may have using our resources.


Your email is only used as the user name to login and in the case of teachers to send weekly reports. We use Twitter to communicate with our users.


Cookies are files with a small amount of data, which may include a unique anonymous identifier. Cookies are sent to your browser from a web site and stored on your computer's hard drive.

We use cookies when you sign in to create a user session. You can instruct your browser to refuse all cookies. However, if you do not accept cookies, you will not be able to start a session.

Google uses cookies to serve ads based on a user's prior visits. Google's use of the DoubleClick cookie enables it and its partners to serve ads based on previous visits to other sites. Users may opt-out of the use of the DoubleClick cookie for interest-based advertising by visiting Ads Settings. When you log in, ads are not displayed.


The security of your Personal Information is important to us, but no method of transmission over the Internet is 100% secure. While we strive to use commercially acceptable means to protect your Personal Information, we cannot guarantee its absolute security.

Changes to This Privacy Policy

This Privacy Policy is effective as of November 18, 2018. Any revisions will take effect once posted on this page.

We reserve the right to update or change our Privacy Policy at any time. You should check this Privacy Policy periodically. Your continued use of the Service after we post any modifications to the Privacy Policy will constitute your acknowledgment of the modifications and your consent to abide and be bound by the modified Privacy Policy.

Contact Us

If you have any questions about this Privacy Policy, please contact us.


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Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
José Rodríguez Alvira.