Privacy

This site is free to read and has no accounts. You are never asked to sign in, and nothing you type into a quiz is sent anywhere. This page says exactly what does happen.

There is no account, and no advertising

There is no sign-up, no login, and no user record of any kind. The site sells nothing, carries no advertising, and shares no data with advertisers or data brokers. It sets no cookies.

Anonymous page counts

The site's only third-party script is Cloudflare Web Analytics, which counts page views. Like any web request it sends Cloudflare your IP address, the page URL, the page you arrived from, and your browser's user-agent string, but it sets no cookies, does no fingerprinting, and builds no per-reader record.

What is stored in your browser

Your theme choice and your progress through practice sets and chapter tests are saved in your own browser, using local storage rather than cookies. This site never sends any of it anywhere, and clearing your browser's site data for this domain erases it.

Links to other sites

Lessons link to outside references such as OpenStax, Khan Academy, and Math Is Fun. Those sites have their own privacy practices, and this page does not cover them.

Questions

If something here is unclear or looks wrong, get in touch. Corrections are welcome.