N28 · Full next teaching

Previous target

V07D

Target

Compare equal quantities rather than ticket prices

Flexible time

About 8–12 minutes, or shorter visits; unpiloted suggestion.

Prepare

Use scrap paper, group labels and appropriate large counters, or dictate a complete model to a scribe. Work at a table; no purchase, household data or public performance. Keep teacher worked material separate from blank learner spaces.

Complete new neutral task

Exactly 24 blank picture cards are required. Offer A: 4 for a made-up $20; B: 6 for $24. Whole packs only and no extras. Compare full costs and explain the cheaper plan.

Specific criterion

Use whole packs to supply the same target quantity and compare full costs with contextual units.

Whole teaching sequence

Read the new brief and ask which quantity is missing. Name units before any calculation. Draw a row for the required quantity, then make each whole-pack plan against that same row. Record pack count, total items and total cost in separate columns. Compare costs only after both quantities match.

Build the supplied new example together. Teacher explanation: A:6 packs,24 items,$120. B:4 packs,24 items,$96. B costs $24 less. Ask the learner to point to the part of the model that supports each quantity. A smaller printed pack price can cost more to supply the same quantity.

Remove the worked example. Give this changed task privately: Exactly 48 items are now required, with the same whole-pack offers. Compare again. Offer a different response mode if needed without silently changing the mathematical criterion.

Supplied joint model

A:6 packs,24 items,$120. B:4 packs,24 items,$96. B costs $24 less.

Equivalent offers

Make/draw using original blank group frames.

Explain/sign/point or dictate reasoning.

Type a private note or use paper; a device is optional.

Private changed task after removing model

Exactly 48 items are now required, with the same whole-pack offers. Compare again.

Staff changed-task possibility

A:12 packs/$240; B:8 packs/$192; quantities both 48.

Observe and decide next teaching

Check the changed response against the named criterion, not against speed, spelling or a preferred-looking diagram. Record the exact support given. If the meaning is still unclear, revisit one group or one constraint with a smaller supplied number, record the change and return later to the original demand.