Several ideas may meet a need. Compare each with the same criteria and constraints. Likely means a prediction, not a measured result. If evidence is missing, uncertain is a better rating than an invented pass. Safety: Paper planning only; no actual cutting or fastening tools. Stop: End with one selected proposal. Do not silently turn predicted ratings into test results.

Materials: Paper, pencil and ruler; One reused sheet available to inspect; no construction required 1. Use this defined problem: keep one wooden pencil from rolling on a flat desk. Criteria: fits inside a 15 cm by 15 cm footprint and blocks sideways rolling. Constraints: one reused sheet, no tape, no cutting, no extra objects. 2. Generate three different sketches. If stuck, use these teaching seeds and change a feature: folded channel with raised sides; folded sleeve around the pencil; low accordion trough. Draw where the pencil rests in each and label your change. 3. Make a table Idea | Blocks rolling? | Fits? | One sheet? | No tape/cutting? Record likely yes, likely no or uncertain for each. Estimate dimensions from the available sheet and label estimates. 4. For every rating, point to a feature in the sketch or a stated material limit. Do not give a high score just because a design looks attractive. A solution that violates a constraint cannot be selected unchanged. 5. Select one promising design and explain two criterion-based reasons. Name one uncertainty a future prototype test should check. You are selecting a proposal today, not announcing a tested winner. Done: Three distinct proposals have ratings for every criterion and constraint, with a reasoned selection and a stated uncertainty. Proof: Keep all sketches and the comparison table. Note supplied seed use and adult suggestions. Stop: End with one selected proposal. Do not silently turn predicted ratings into test results.