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Explorations in Intuitive Probability for Levels 1-3

Learning Areas: Number, Language

Essential Skills

• Numeracy
• Problem Solving
• Communication

Have on hand a bucket of coloured counters of two colours only - eg green and blue.

Explain to the students that you are going to get them to close their eyes and pick two counters, one after another from the bucket.

• have each student in turn guess (predict) what colour counter they will pick out first and what colour counter they will pick out second. Write down these predictions

Each pupil picks out their two counters and names the colours of each. After each child chooses …

1. how many students predicted correctly?
2. seat the students in the groups they achieve, eg blue/blue, green/green, blue/green.

Did we get more people in one group than the others? What do they think will happen if they try it all again? Go through the process several times and note the results.

Introduce the idea that picking out one of each colour has more chance of happening than picking out two of the same colour.

1. Take out half of the number of green counters in the bucket.
2. What do the students think will happen? Why?
3. Try picking out counters to test their ideas.

Keep gradually removing green counters to show that the probability moves more towards picking out blue counters. Can the students give any reasons as to why this is so?

1. list all the words the students used to describe the combinations of counters they picked out and the chances of events they predicted.
2. make a green and blue 'counter book' or mobile using these words.

Now put equal amounts of three colours of counters in the bucket. Have pupils predict what colour combinations they could get when picking up two counters only, eg red/blue, red/green, green/green, blue/blue, red/red/,

1. tally them and record as students pick counters up from the bucket
2. keep picking up until the students are satisfied there are no more combinations

Increase the number of colours in the bucket and predict …

1. which combinations are more likely than others? Why?
2. how many combinations are possible

Test out all predictions and tally results.

1. Make bar graphs, pictograms of the results

Make a Probability Line. Use appropriate language for the three points on the line, eg

Have the children place ideas and sentences in the appropriate columns of the probability line for everyday situations, eg

it will rain tomorrow
the sun will rise tomorrow
ten cars will pass the school in the next ten minutes
30 people will walk past the school between now and 10am
the sun will set in the east

Use the probability line/chart on a regular basis to refine ideas of probability and certainty.

Develop a 'Vocabulary of Chance' list.