The note
How schools teach it now
Probability isn't in the primary curriculum (it starts at secondary school), but many 11+ papers include it. Children place events on a scale from 0 (impossible) to 1 (certain) and write a probability as a fraction: ways it can happen over all possible outcomes.
5-minute kitchen-table activity
Put 3 red, 2 blue and 5 green sweets in a bag. 'What's the chance of picking blue?' (2/10 = 1/5.) Pick one, put it back and repeat 20 times. How close did you get?
Worked example
A bag has 3 red, 5 blue and 4 yellow counters. What is the probability of picking a blue counter?
- Count all the counters: 3 + 5 + 4 = 12.
- There are 5 blue counters.
- Probability = blue counters over all counters.
Answer: 5/12
Common mistakes to watch for
- Writing a probability as a ratio (5:7) instead of a fraction (5/12).
- Forgetting to count every possible outcome.
- Thinking a coin is 'due' a head after several tails.
Encouragement
- Try saying
- “How many ways can it happen, out of how many?”
- Rather than
- “It's all just luck.”