Invariants, casework, and pigeonhole readiness

Use elementary olympiad-style methods such as invariant tracking, organized cases, and guarantee reasoning in visible puzzle settings.

Variation ladder

1Foundation recognitionNotice the relevant quantity, shape, relation, or constraint before calculating.Attention to the relevant objects, relation, or constraint without solving it.
2Guided strategyUse a visible scaffold, model, or narrowing move to choose a valid next step.One scaffolded move, then completion of the decision.
3Core taskSolve the target skill independently.Progressive hints that preserve independent evidence before reveal.
4Transfer formApply the same idea when numbers, wording, or representation changes.The invariant idea and what changed in the representation.
5Challenge extensionCombine the skill with a second idea, hidden constraint, or explanation requirement.Smaller case, counterexample, or explanation before reveal.
6Advanced enrichmentReason about the general method or a non-routine variant.Method hint, not the answer; no copied external source text.

Common slips

Tests a few cases and assumes the pattern is proved.

Tracks a quantity that does not actually stay fixed.

Hints and checks

Decision restated without adding a new method.

Common slip nudge: Tests a few cases and assumes the pattern is proved.

One useful scaffold after help is requested.

Non-routine reasoning around the same core idea.