Unit price, total cost, and durability

Objective. Unit price, total cost, and durability:apply the stated method to a concrete case,produce the requested evidence,and justify safe,private,and accessible choices.

About 25–50 minutes. The due date is chosen by a parent.

Split across sittings as needed;no timer or required date.Adult approval remains required even for independent work.

Materials: paper, pencil, optional calculator.

A consumer decision compares total cost across the expected useful life. Include required supplies, maintenance, delivery, and usable lifespan when the scenario provides them. Estimates are uncertain, so label assumptions. A low upfront price can still be suitable when cash or access is limited. These are pretend comparisons, no product recommendation or purchase. Safety and boundaries: All money, prices, accounts, and contracts are fictional. No banking login, card, credit application, signature, purchase, transfer, complaint send, or family income disclosure. Family-only evidence;use fictional details,no faces or private records.No purchases are required.

Worked example

Unscored model for discussion;use the assignment case for your own work.

A$20 item lasting 40 uses costs$0.50 per use before extras; a$30 item lasting 100 uses costs$0.30 if those estimates hold.

Unit price, total cost, and durability — evidence and reflection

1. Compare$18 for 30 uses and$28 for 70 uses. Find cost per use.
2. Add a required$7 supply to the second option. Recalculate its cost per use.
3. Create a decision matrix with upfront cost, estimated lifespan, access, and repairability.
4. Explain why a lifespan estimate should not be treated as a promise.
5. Spiral review — A four-wrap plan lists only three tortillas. Find the mismatch and a no-purchase fix. Spiral review.

Acceptance checks

Address every numbered task with labeled,legible evidence and reasoning.
Use fictional records and family-only submissions;no public posting or sensitive personal data.
Paper/simulation earns the same credit as an approved physical demonstration.
Follow adult supervision,allergy,and stop rules;do not perform a hazard to prove understanding.
Completion records evidence present;accuracy,independence,and safety mastery are reviewed separately.

An adult supervises. This stays in the family. Spending is a simulation, not real money.

For any optional food,adult verifies all ingredients and established allergy needs;avoid cross-contact,no tolerance tests,and use paper food if uncertain.For clothing/cleaning,adult checks sensitivities and labels;no chemical mixing.

All money, prices, accounts, and contracts are fictional. No banking login, card, credit application, signature, purchase, transfer, complaint send, or family income disclosure.

Complete the entire task using paper diagrams,fictional data,empty/inactive tools,and parent-observed explanation.

No unsupervised heat,sharp tools,cleaners,or appliances.
No raw-meat handling,unsafe food tasting,chemical mixing,flame/smoke experiments,or electrical repair.
No real childcare/medical/intimate care,financial transactions,credentials,private records,or public posting.

Required. Read the complete on-page teaching/model with a parent or independently;external sites are not required.
Optional. Use one verified free reading for another explanation.Follow readingFocus and course safety/privacy limits.Skip external worksheets or steps asking for private data,purchases,or actions.

If this is still shaky. Use this lesson’s worked model to make a three-box process card.Label the goal,one safety/constraint check,and the evidence you would show.Explain it to a parent before trying the main task again.

Optional extra. Change one fictional constraint in this lesson,such as available time,access,ingredient restriction,or pretend cost.Revise one artifact and show what must change and what safety/privacy rule stays fixed.

Turn in a typed answer, a JPEG, PNG, or WebP photo, a PDF scan, or an MP3, WAV, M4A, MP4, or WebM file up to 4 MB. A parent can log paper. One https address is stored as text and is not opened or run. Zip and code files are refused.

Creating a Buying Plan
Read big idea/objectives; use our fictional buying scenarios. Do not write a public blog, shop, or make a purchase.
· Opening this link does not submit the lesson.

This is a preview. A parent assigns the lesson and chooses the due date after the student is enrolled. The answer key is not on this page.

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