# Three jobs, one collection

Make three different useful parts, then change two boundaries or memberships. An ordinary starting amount is 28; smaller useful amounts are welcome. Use safe existing pieces, paper marks, tactile materials or direct the moves. Keep or revise your plan with a reason.

[Empty own organiser](../aids/own-parts.svg) · [Complete description](../aids/own-parts-alternative.md).

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Look for all three counted once and no hidden equal-sharing requirement. A supplied example is 10 + 8 + 10 = 28; choose it as teaching support after an own attempt when useful. If the third part is omitted, put every object in one of three distinct places and audit coverage. If fairness distracts from the target, choose three jobs that deliberately need different amounts. [Full plan](../teacher/day-47.md). Count supplied versus actual materials separately; child-directed adult acts show mathematical choice without proving motor performance. No viewer, returned homework or fixed quota is required.

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