Class Shop Modeling: Designed by Pupils

Warning: Your screen size is quite small for viewing this. Rotate your device into landscape mode if you can.

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

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

Watch as we build one class shop together on screen. Each thing we want to sell goes in as its own line. The bar at the top shows how much of our €50 starting float we have spent on stock. Remember, this is what the stock COST us to buy, not what we will charge customers.

Now we work out two more numbers beside the bar. First, the takings — that is all the money customers will hand over during the day. If 28 pupils each spend about €1.20, the takings come to about 28 × €1.20 ≈ €33.60.

Key point

Then the profit — that is what is left over once we take the cost of the stock away from the takings. So takings €33.60 minus stock that cost about €18 leaves a profit of about €15.60. Profit, not takings, is the number that tells us whether the shop did well.

Teacher Notes

The interactive on screen tracks stock allocation against the €50 cap only — it does not work out takings or profit. Keep a clear side area of the board for those two numbers. Walk them slowly: this is what the stock cost us — this is what we think the customers will pay in — and this is what's left over once we take one from the other.

Hold the class on that profit number. Many pupils think a shop did well if it took in a lot of money; the difference between takings and profit is the whole point of the lesson.

Six items entered against the €50 cap, stock cost coming to about €18 so it sits well below the takings.
Predicted takings: 28 pupils × about €1.20 each ≈ €33.60, written on the board beside the bar.
Profit: takings − stock cost = about €33.60 − €18 ≈ €15.60.

👇 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, spread the starting float across the items so the stock you buy stays under the ceiling shown, 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. To find 10% off, first find one-tenth of the price, then take that away. For example, 10% of €2 is 20c, so €2 minus 20c makes it €1.80. Decide whether dropping the price makes more total profit because you sell more of it.

Balance three class shops

Teacher Notes

This round is the practice bank — 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.

For the promotion shop, model the method on the board first: find one-tenth, then subtract — 10% off a €2 item makes it €1.80, not €1.90. Ask the class whether selling more at a lower price could beat selling fewer at the full price. Confirm each allocation lands under the stock ceiling so there is room left for profit before checking.

+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 115 · Class Shop Modeling: Designed by Pupils

Download Activity Book page (PDF)

End of lesson

123learn · Online learning platform

Unlock the full learning experience

You're previewing this lesson. Get full access to this lesson and hundreds more — each one ready to teach, with interactive activities, printable resources and pupil progress tracking built in.

Hundreds of curriculum-aligned lessons

Interactive activities in every lesson

Printable resources & progress tracking

Get started

Copyright Notice
This lesson is copyright of 123Learn.ie 2017 - 2025. Unauthorised use, copying or distribution is not allowed.

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

Coming up

Unlock the full learning experience

XP