Best for
After the scenario analysis, as the numeracy application in Lesson 5.
Applied numeracy • Years 7–8 • Unit 10 Week 5
Budget Constraint Analysis
A budget constraint is a line you cannot cross. This sheet makes you build a week of meals inside one, then work out exactly what each decision cost you in the things you did not buy.
Free to teach tomorrow, adaptable to your rohe
Sample prices are provided so the sheet works without preparation. Te Wānanga is useful when you want your own region's prices built in.
- Replace the sample prices with this week's prices from your local supermarket.
- Generate an easier version with fewer items and a rounder budget.
- Save an adapted Unit 10 budget task in My Kete.
Kaiako planning snapshot
- Use length: 20–25 minutes.
- Grouping: Individually, then compare totals in pairs.
- Prep: None. Calculators optional — the arithmetic is deliberately manageable.
- Teaching move: When a student comes in under budget, ask what they left out. That is usually where the nutrition trade-off is hiding.
What this sheet already gives you
- A fixed weekly budget and a sample price list
- A planning table for seven days
- An opportunity cost calculation for two decisions
- A stretch task that changes the constraint mid-week
- A reflection connecting the numbers to Lesson 5's scenarios
The stretch task — cutting the budget by a quarter after the plan is made — reproduces what an unexpected bill does to a real household. It is the most useful part of this sheet.
Ngā Whāinga Ako / Learning Intentions
- We are learning to plan within a fixed budget constraint.
- We are learning to calculate the opportunity cost of a spending decision.
- We are learning to explain how a constraint changes what counts as a good decision.
Ngā Paearu Angitū / Success Criteria
- My weekly plan stays within the budget and covers seven days.
- I can state the opportunity cost of two of my decisions in money and in food.
- I can explain what happened to my plan when the constraint changed.
Your constraint
You are planning food for a household of four for one week. Your budget is $150. You cannot go over it.
Sample prices for the task — replace them with real prices from your supermarket if your kaiako asks you to.
| Item | Price | Item | Price |
|---|---|---|---|
| Rice, 5 kg | $12 | Fresh fruit, 1 kg | $12 |
| Potatoes, 5 kg | $9 | Frozen vegetables, 1 kg | $4 |
| Instant noodles, per serve | $0.50 | Fresh vegetables, 1 kg | $7 |
| Mince, 1 kg | $15 | Bread, 1 loaf | $3 |
| Eggs, dozen | $9 | Milk, 2 L | $4 |
| Tinned fish, 1 tin | $3 | Cheese, 500 g | $9 |
Plan the week
| Day | What the household eats | Cost |
|---|---|---|
| Monday | $______ | |
| Tuesday | $______ | |
| Wednesday | $______ | |
| Thursday | $______ | |
| Friday | $______ | |
| Saturday | $______ | |
| Sunday | $______ | |
| Total | $______ |
What did it cost you?
Opportunity cost is not the money you spent. It is the thing you did not get.
| Decision I made | What I gave up to make it | Opportunity cost in words |
|---|---|---|
Stretch: the constraint changes
A bill arrives. Your budget for the week is now $110, and your plan is already made. Which three things do you change first, and what is the nutritional cost of those changes?
| What I change | Why this one first | What the household loses |
|---|---|---|
Reflect
Look back at Scenario A in the Trade-off Scenarios: $180 a week for six people. Your budget was $150 for four. Whose constraint was tighter, and what does that mean for the quality of the decisions they can make?