Choose your path

Every problem follows the same loop: problem → try it → hint → solution. Hints get stronger one at a time.

Grade recommendations

Grade only tunes recommendations — every path and problem stays unlocked.

Equations, sequences, clever factoring.

Angles, areas, similar triangles.

Divisibility, mods, primes.

Counting, expectation, fair games.

Contest-style warmups, 25 per set.

Harder contest sets and tactics.

Limits, derivatives, integrals.