Proof and counterexample artifacts
Produce a visible example, counterexample, or short proof artifact that justifies or rejects a mathematical claim.
Core · Proof and counterexample artifacts · Independent practice · Evidence Proof
Loading
Watch: Watch whether the learner makes the center worth more than all 24 non-center tiles together and pairs every pre-center move with its half-turn partner; those two features are the decisive evidence.
Misread: A learner may treat a diagonal gap as open, think “largest” means “more than the other 24 together,” or stop after choosing No instead of building the value rule and full Player 2 strategy.
Curriculum: This task develops counterexample reasoning for a universal claim, 180-degree symmetry on an odd grid, legal-move invariants, and comparison of a part with half of a total.