Class Shop Modeling: Designed by Pupils

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1 Getting Started
2 Watch and Notice
3 Try It Together
4 Sketch Your Price List in Your Copy
5 Class Challenge
6 What Did We Notice?
7 What's Next
Pupil practice

1 - Getting Started ~4 mins

Illustration for Getting Started Imagine our class is opening a shop for one day. You have €50 to start with, six things to sell, and a whole class of hungry customers waiting at the door. Here is the big question: what would you put on the shelves, and what would you charge for each thing?

Key point

Remember, the €50 is what we PAY to buy the stock. The price we CHARGE the customer for each thing is a different price, and it is usually a bit higher. Have a think before any hands go up: would you stock lots of cheap things, or a few expensive ones?

Teacher Notes

Take three or four hands-up answers, not open call-outs. Don't price anything yet — just gather a spread of ideas. Give five seconds of quiet think-time before any hands go up so the quieter pupils get a fair start.

👇 Mark your steps as done as you complete them.

+5 XP

2 - Watch and Notice ~9 mins

We will build one class shop together on screen, adding each item we want to sell as its own line. The bar at the top tracks how much of our €50 float we have spent on stock — that is what the stock COST us, not what we will charge. Then we work out two more numbers beside the bar: the takings and the profit. Watch which of those two really tells us whether the shop did well.

Teacher Notes

Interactive tracks stock against the €50 cap only — it does NOT do takings or profit. Keep a side area of the board clear for those two.

Enter six items against the cap; stock cost lands about €18, well below takings.

Takings: 28 pupils × about €1.20 each ≈ €33.60 — write it beside the bar.

Profit: takings − stock cost = about €33.60 − €18 ≈ €15.60.

Walk it slowly: what stock cost us, what customers pay in, what's left over.

Hold the class on the profit figure. Many think a shop did well if it took in a lot — the takings vs profit distinction is the whole point.

👇 Mark your steps as done as you complete them.

+10 XP

3 - Try It Together ~12 mins

Now we design one class shop together. You call out the six things you want to sell, and we put each one in as its own line. Watch the bar fill up: it shows how much of our €50 starting float we have spent buying the stock. If one line tips us over €50, we rebalance.

Key point

Once the stock is in, we work out two things together on the board beside the bar: how much we think the class will spend (the takings), and how much profit that leaves once the stock is paid for.

Design our shop within €50

Teacher Notes

This round is for talking it through together — pupils take turns at the board and the class agrees or corrects out loud. The interactive only tracks stock against the €50 cap, so keep a side area of the board for the takings (28 × €1.20) and the profit subtraction.

Ask the class to predict takings using a friendly estimate: if each of 28 of us spends about €1.20, what does the whole class spend? Revoice a strong answer: so 28 lots of €1.20 is about €33.60.

Watch for pupils who name a big takings figure and call it profit — stop and ask but what did the stock cost us? Keep the board work brisk; the open exploration is the point, not perfect prices.

+15 XP

4 - Sketch Your Price List in Your Copy ~3 mins

COPYBOOK MOMENT

In your maths copy, sketch your shop's price list with the six items priced. Underneath the list, write three separate lines:

Starting float
Predicted takings
Predicted profit

Keep each one on its own line so you can read your plan at a glance.

Teacher Notes

Walk the room glancing that the three lines are separate and that profit is takings minus stock cost, not the same as takings — no marking, this is whole-class copybook practice.

+10 XP

5 - Class Challenge ~14 mins

Today we work through several class shops, one at a time. For each one, check the stock allocation across the items stays under the ceiling shown with none left empty, leaving room for a profit. Then work out the takings and the profit on the board.

Worked example

The last shop adds a stretch twist: put a 10% promotion on a slow-selling item and check whether total profit goes up. First change the price: find one-tenth, then subtract. Next compare profit before and after with real sales numbers on the board. Stock cost stays the same either way. The promotion wins when the extra sales more than cover the lower price.

Balance three class shops

Teacher Notes

These are the practice questions. Pupils take turns at the board, check each answer, and the class confirms before moving on. Keep the board work brisk rather than over-explaining.

Shops A to C: the interactive only tracks stock against the cap. Confirm each allocation hits the required total with none left empty, then work takings and profit beside it on the board.

Shop D promotion, model the full method on the board before pupils try:

1. Price cut: one-tenth of €2 is 20c, new price €1.80 (not €1.90).

2. Before: 5 sold × €2 = €10 takings from that item.

3. After: 12 sold × €1.80 = €21.60.

4. Stock cost unchanged, so profit rises by €11.60. Promotion wins.

Slip to watch: pupils who cut the price but keep the same sales number, or who call the new takings the profit. Ask did we sell more, and is stock cost the same?

+15 XP

6 - What Did We Notice? ~3 mins

MATHS TALK

What is the difference between takings and profit? If two shops both took in €33.60, could one have done well and the other badly? Which number tells you the shop was a success?

Teacher Notes

Listen for pupils naming the stock cost as the thing that separates takings from profit. Revoice a strong answer: so a shop can take in loads of money and still make almost no profit if the stock cost nearly as much. Head off the idea that the biggest takings always means the best shop — the profit line is the real measure.

+10 XP

7 - What's Next ~2 mins

What we did today

Priced six items so the stock fit inside a starting float.
Predicted the takings from a whole class of customers.
Worked out profit as takings minus the cost of the stock.
Tested whether a promotion can make more total profit.

Coming up

Next we plan a real class trip, weighing up time, money and distance to choose between two days out that both have to fit a budget.

Teacher Notes

Close by reminding the class that profit, not takings, is the number a real shopkeeper watches.

+5 XP

Pupil practice

Module 9 · Mathematical Modeling and End-of-year Review Mixed

Lesson 111 · Class Shop Modeling: Designed by Pupils

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Teacher Class Feed

1 - Getting Started ~4 mins

2 - Watch and Notice ~9 mins

3 - Try It Together ~12 mins

Design our shop within €50

4 - Sketch Your Price List in Your Copy ~3 mins

5 - Class Challenge ~14 mins

Balance three class shops

6 - What Did We Notice? ~3 mins

7 - What's Next ~2 mins

What we did today

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