1. An advert for a chicken burger has been banned after the Advertising Standards Agency decided that the actual burger was smaller than the burger shown in the video.

2. Does this burger appear too large? How could you find out?

3. How big are the average-sized man’s hands? How big would this burger be in real life?

4. It’s in the News! Big Burger Teacher Notes

5. Big Burger Introduction: We might suspect that television advertising exaggerates in order to convince us that the product is bigger and better than it is in reality, but how could we prove it? A recent advertisement for a chicken burger was banned by the Advertising Standards Agency because, when they bought three of the real burgers, they found that the thickness, the quantity of additional fillings and the overall height of the product was “considerably less” than that advertised. This resource offers a context for students to explore how they might investigate a claim and model a situation using both data handling and proportional reasoning. Content objectives: This context provides the opportunity for teachers and students to explore a number of objectives. Some that may be addressed are: calculate statistics and select those most appropriate to the problem or which address the questions posed design a survey or experiment to capture the necessary data from one or more sources; design, trial and if necessary refine data collection sheets; construct tables for gathering large discrete and continuous sets of raw data, choosing suitable class intervals write about and discuss the results of a statistical enquiry using ICT as appropriate; justify the methods used interpret and use ratio in a range of contexts. Process objectives: These will depend on the amount of freedom you allow your class with the activity. It might be worth considering how you’re going to deliver the activity and highlighting the processes that this will allow on the diagram below:

6. Activity: The activity introduces students to the decision of the Advertising Standards Agency about a burger advert in which they “concluded that the visuals in the ad were likely to mislead viewers as to the size and composition of the product”. This context offers several different explorations. After the first slide or two you might like to invite students to discuss and explore how they would investigate whether the burger in the advert appears too large. You might choose to use this as a context to explore surveys and types of average (as the ASA ruling includes the ‘average-sized’ man) and you could then use this as a context to explore proportion and how large the burger could be. There are a number of routes available to both you and your students. Differentiation: You may decide to change the level of challenge for your group. To make the task easier you could consider: providing some scaffolding to support the students’ writing initiating a discussion about whether the burger ‘looks too big’ and what this might mean providing an average hand size and inviting the students to use resource sheet 1 to predict how big the burger shown is. To make the task more complex you could consider: reducing the scaffolding, asking the students to work through each of the four stages of the data handling cycle to work towards a solution suggesting that students take the role of an imaginary Burger King representative and develop a survey which might show that the burger shown is a representative size. This resource is designed to be adapted to your requirements. Working in groups: This activity lends itself to paired work and small group work and, by encouraging students to work collaboratively, it is likely that you will allow them access to more of the key processes than if they were to work individually. You will need to think about how your class will work on this task. Will they work in pairs, threes or larger groups? If pupils are not used to working in groups in mathematics you may wish to spend some time talking about their rules and procedures to maximise the effectiveness and engagement of pupils in group work (You may wish to look at the SNS Pedagogy and practice pack Unit 10: Guidance for groupwork). You may wish to encourage the groups to delegate different areas of responsibility to specific group members. Assessment: You may wish to consider how you will assess the task and how you will record your assessment. This could include developing the assessment criteria with your class. You might choose to focus on the content objectives or on the process objectives. You might decide that this activity lends itself to comment-only marking or to student self-assessment. If you use the APP model of assessment then you might use this activity to help you in building a picture of your students’ understanding. Assessment criteria to focus on might be: use and interpret mathematical symbols and diagrams (Using and applying mathematics level 3) develop own strategies for solving problems (Using and applying mathematics level 4) ask questions, plan how to answer them and collect the data required (Handling data level 5) communicate interpretations and results of a statistical survey using selected tables, graphs and diagrams in support (Handling data level 6).

7. Probing questions: These might include: what would convince you that the burger is/isn’t a representative size? how likely is it that the actor in the advert has small hands and that the burger is representative? How big would the man’s hands be if this were the case? how many people would you survey to find the average hand size? what does the phrase ‘average-sized’ man mean in this context? You will need: The PowerPoint presentation and resource sheet. The PowerPoint has three slides: The first two slides set the scene, showing students the news story from the BBC website. The second slide poses the questions ‘Is this burger too big? How could you find out?’ The final slide gives a little more detail about the ruling and the methodology of the ASA and poses two further questions ‘How big are the average-sized man’s hands?’ and ‘How big would this burger be in real life?’

8. Student Resource Sheet