Friday, 29 June 2012

Revelling in Probability

When learning about probability we use Revels. Yes, the chocolates. The whole brand of Revels is about which flavour you will eat, the likelihood of getting one you don't like and hoping for your favourite. That's probability in the 'real world' of a Key Stage Two child!


Step one is to introduce the children to the language of probability and particularly why it's important to be careful when using 'certain', 'impossible' or 'even chance'. Do 'Play Your Cards Right', coin toss and other examples if needed. Then go back to discuss the likelihood of getting a certain flavour when selecting a Revel. We found the children expected there would be equal chances of picking out each flavour. We have used some of the Revels TV commercials to further explain the marketing behind this product:


We placed a packed of revels on each table to be shared between 6 to 8 children. Now, in order to be able to state the probability of getting a certain flavour we need to find out if the Revel flavours are evenly distributed. Well, there's only one way to find out! Next, comes eating and tallying. The children eat the revels and tally the total amount of each flavour eaten.


Gather the information from each table about how many of each flavour were in their packs. This now offers the opportunity to calculate some averages. For example, Toffee: 7, 8, 9, 9, 14. From this data the mean, median, mode and range for each flavour per packet can be calculated, then maybe even converted into percentages. 
It now becomes apparent that the spread of flavours is NOT equal and in fact quite consistently biased towards one flavour! In addition to this the range can be quite broad from one packed to another. After looking at the data and discussing what it shows we wrote letters to Mars (address is on the packet) and hope to get a response from them. The letters offered a link to our persuasive writing topic and involved the children needing to include data to back up their arguments.

A fun filled lesson or two. The children learned a lot about probability and also had the opportunity to write to a real company about their findings.

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