Whole packs and purchase cost

Choose this companion from student work

Use this addition to Compare Unit Rates on the Same Basis when a learner can calculate dollars per item but treats the lower unit price as an automatic guarantee of the lower purchase total. The new demand is to check how many whole packs meet the stated need before deciding.

For selected Grade 6 learners who can interpret unit price, multiply whole numbers and explain equal groups. This is one focused response pathway, not a placement test or a complete course. All prices and example responses are fictional teaching material.

Before choosing the lesson

If existing work does not show the reasoning clearly, give Starting task alone. Ask neutrally, “What does each amount count?” and “What is the shop allowed to sell?” Wait for a response before showing the model. A blank, unclear explanation or arithmetic slip does not establish the same teaching need.

Per-one meaning or units insecure: return to Find and Interpret Per One.
Whole-number group roles insecure: return to Equal Groups and Equal Shares.
Unit prices and complete-pack totals secure: ask for the reason and proceed to different follow-up or later transfer, rather than repeating the model.

Prepare and keep later work separate

Print Starting task only if new entry evidence is needed. Select Lesson and practice after interpreting the response. Keep Follow-up check and Later transfer unused until their planned occasion. Keep Teacher guide and answers with the teacher. The complete ZIP contains answers and later tasks; share selected pages, not the ZIP.

The online resource page links every format. The offline package includes this companion plus the unchanged comparison lesson and its teacher guide in first-teaching. Use those prerequisite files if the common-basis comparison needs introduction. They contain familiar instruction and answers, not new checks.

Whole packs and purchase cost

Use the response and look again

File	Pages and use
Starting task	1 student page before any model when entry reasoning is unknown.
Lesson and practice	3 student pages: model, guided work, then practice with a changed need.
Follow-up check	2 student pages after teaching. Give both together; no model, price calculations or filled table are supplied.
Later transfer	2 student pages at another learning opportunity. Whole rolls and measured length add a demand.
Teacher guide	5 teacher pages with scripts, keys, alternatives and interpretation.
Decision record	1 teacher page for exposure, support and the next teaching choice.

For guided work, stop after the learner builds a feasible purchase; do not supply all the answers in advance. The model is teaching. Practice with help is supported evidence. Follow-up becomes practice if its problem or key has already been seen.

Keep access and reasoning visible

Read directions aloud, enlarge text, use speech-to-text or allow an oral response with labeled drawings. Blank tables or learner-made pack sketches can preserve the target. Read “at least” as “enough, possibly with extras”; do not tell the learner how many packs to buy. If you provide pack counts or a supplier choice, the task no longer independently checks that reasoning. Record any calculator or other support.

A successful response supports a tentative decision about this task: unit price, feasible pack count, total paid and a reason. The later roll task is different, not an equivalent test form. These tasks have not established classroom effectiveness, equal difficulty or retention.

Mentor Teaching. Teachers may print and adapt this original companion under the site Terms of Use. Retain attribution and identify local changes. Check print preview after editing Word files. Keep student notes locally under school procedures.