# C16 · After-own staff

## Complete neutral brief

Need exactly 24 items for a fictional community display. Pretend A packs 6 for $18; B packs 8 for $32. Whole packs and no extras. Compare full costs for the same quantity. Work out the whole-dollar cost of one item in each offer. Explain how those unit costs help you check the full-cost comparison.

## Specific criterion

Compare two whole-pack offers for the same required quantity and explain a whole-dollar unit cost.

## One staff worked possibility

A:4 packs/$72. B:3 packs/$96. Both supply 24 items; A costs $24 less. A costs $18 ÷ 6 = $3 per item; B costs $32 ÷ 8 = $4 per item. For 24 items, 24 × $3 = $72 and 24 × $4 = $96, matching the whole-pack totals.

## Neutral support limit

Ask one neutral 'What does that amount count?' question if necessary and record it. Teach afterwards rather than covertly supplying the model.

## Evidence scope

An individual response in a selected mode. Read/scribe if needed and record support; hide the teacher model first. Formative partial evidence, not an annual grade.