Working prototype. Algebra and quadratics.
Lesson playerFactoring x² + bx + c. Nine steps, graded server-side. The graph question works by mouse or keyboard. Student viewThree items exactly as a student sees them — no standards, no prerequisites, and no answer key in the page. Try getting one wrong. What was squared?Square roots. Drag the edge of a square until the area reads the number you were given, then do the same with the foot of a ladder. Touch any part of the figure to find out what it is. Euclid, rule and compassConstruction sheets you draw on. Two lessons — Elements III.20, the angle at the centre, and I.32, the exterior angle it cites — and a blank sheet with the instruments and four of Euclid's own constructions. Lesson libraryFifteen lessons on quadratics, each tagged with a Common Core standard and its prerequisites. Item renderer (diagnostic)The developer view of the same items, showing the metadata a student never sees.