Practice that is easier to use
We aim to support keyboard navigation, readable contrast, clear form labels, and screen readers. You can navigate answer choices using standard radio-button keyboard controls. Explanations and results are available as text, and practice has no enforced time limit.
Every practice question is also available on a topic page, with an expandable text explanation. You can use those pages if you prefer reading and paper practice. The graph workspace also describes computed intersections in text.
Browser and privacy choices
No account is required. We use no tracking cookies, and browser-saved practice can be cleared from the tool. Disabling analytics does not prevent practice. JavaScript is required for interactive scoring; the question library remains readable without it.
Report a barrier
If something makes this site difficult to use, contact Urban Algorithm. Include the page, what you were trying to do, and any browser or assistive technology details you are comfortable sharing.