Manually worked fictional illustration; not model-tested output. ### 1. Focus and readiness DRAFT_FOR_ADULT_REVIEW. PROPOSED counted-repeat challenge. Goal: marker reaches3 from0. Supplied number/movement routines are prerequisites, not assessed readiness. ### 2. Materials and time One pair uses1 strip,1 large paper marker,1 pencil; totals match stock. Adult stays present and learners share/alternate roles. Estimated ledger: setup2 + explain/model2 + challenge4 + reflection3 + cleanup1 =12minutes. No printing or outside preparation assumed; adult confirms time and materials before use. ### 3. Learner challenge card Place the marker at0 on the0-4strip. RIGHT means move exactly one cell right. A move beyond4 is invalid and stops the run; no wrap. REPEAT n {RIGHT} means do RIGHT exactly n times; n may be0-4. Choose n to finish at3. Predict the positions, then run your written program. Reset to0 before every attempt; do not add moves during a run. Explain why your chosen count works. Swap who reads and who moves using the same stock. ### 4. Facilitator key and traces Separate key: one valid solution REPEAT3 {RIGHT}. Start0; iteration1 RIGHT ->1; iteration2 ->2; iteration3 ->3; repeat ends, halt at goal. Three primitive actions, within12. Deliberate bug REPEAT2 {RIGHT}: reset0 ->1 ->2 ->halt, short of3. First missing action is the intended third repetition. Repair count2 to3; reset0 ->1 ->2 ->3 ->halt. Zero check REPEAT0 {RIGHT}: start0 ->no body actions ->halt0, not goal. No other rule changes or uniqueness/minimum claim. ### 5. Hints and transfer Hint1: point to start and goal. Hint2: count one RIGHT per cell crossed. Hint3: compare predicted positions with repeat count. Keep written numbers plus hand-drawn marks; adult confirms representation. Optional discussion: what count reaches2? Expected2, with0 ->1 ->2; use only if adult finds time, not an added required phase. ### 6. Adult rehearsal and open checks Draft rule/trace and stock arithmetic are shown, not classroom tested. Adult must physically rehearse the valid, wrong-count, repaired and zero runs; check marker size/participation and timing. Keep this key away from the learner card. Next: rehearse the stated rules before using the challenge.