Probability (A Game)

My year 8 class had spend time discussing ‘odds’ in gambling and we talked about the recent match between Spurs and Liverpool. I said the odds for Spurs to win meant that if I placed a £10 bet and Spurs won then I would receive £20 plus my £10 bet. I thought it might be a good idea to simulate a similar situation without the money.  I showed them a bag of 12 counters and 6 were red, 3 blue, 2 green and 1 yellow. Students would choose where to place 4 marks in their grid (like the one below)

Screen Shot 2018-02-27 at 17.33.09

if i pulled out a counter and they had a tally in the matching box they got those points per mark. So for example if they put a tally in each box and I pulled out a Green counter they would get 6 points but if they put two marks in green then they’d receive 12 points (2 lots of 6)

The person with the highest score after 12 tries won. We also talked about how many of each colour we would expect after 12 attempts.

I asked students to minus 48 from their score and see if it was a negative or positive. Can you think why?

They really enjoyed the task and we then had some great discussions about theory and practical and why how some students chose to place their tallies. Students used language such as ‘I put 2 in red because theres a 50:50 chance it will be red but i also placed one in yellow because although its a 1 in 12 chance but if it does come up then i’ll get 12 points.’

Once we were finished the wining students with the highest points score came up (they had 120 points) and they were allowed to place their 120 marks on the grid. I said i’d only be drawing out one counter. One boy put all points into Red straight away and the girl split hers over Yellow, Green, and Blue. I enjoyed listening to the students comments towards the two winners. I heard things like “don’t put any in Red. He put all his in Red so unless you put all yours in Red you won’t win” “It doesn’t matter how many you put in the other colours” “You have the same chance with your colours as Red”

Then I pulled out a RED counter … cue the whoops and shouts.

The girl said “I had 120 points, i should have just stopped there because now I have nothing”


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