# N19 · Full next teaching

## Previous target

V05C

## Target

Keep a one-off cost separate and check a budget

## 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

6 pretend mini-game kits cost a made-up $11 each plus one $7 fee. The supplied budget is $80. Find the exact cost and amount left or over. All prices are fictional.

## Specific criterion

Model repeated cost plus one fixed fee, calculate the exact total and interpret the amount left or over.

## Whole teaching sequence

Read the new brief and ask which quantity is missing. Name units before any calculation. Make a card for each purchased kit and one separate fee card. Join the kit-cost total and the fee once. Put the supplied budget on a third card and compare before subtracting.

Build the supplied new example together. Teacher explanation: 6 × $11 + $7 = $73; $80 − $73 = $7 left. Fee paid once. Ask the learner to point to the part of the model that supports each quantity. A fee charged once is not a fee on each item. The count of items is not a dollar amount.

Remove the worked example. Give this changed task privately: Only the one-off fee increases by $2 to $9. Same kits and budget. What changes and what stays? Offer a different response mode if needed without silently changing the mathematical criterion.

## Supplied joint model

6 × $11 + $7 = $73; $80 − $73 = $7 left. Fee paid once.

## 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

Only the one-off fee increases by $2 to $9. Same kits and budget. What changes and what stays?

## Staff changed-task possibility

Total $75; $5 left. Kit count and repeated cost stay the same.

## 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.