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Great Expectations

Probability through problems
list

Probability through problems

Age
11 to 16
Challenge level
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This collection of articles for teachers outlines an approach for teaching probability at secondary level.
Which team will win?
problem

Which team will win?

Age
11 to 14
Challenge level
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A practical experiment which will introduce students to tree diagrams, and help them to understand that outcomes may not be equally likely.
The dog ate my homework!
problem

The dog ate my homework!

Age
11 to 16
Challenge level
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A practical experiment which uses tree diagrams to help students understand the nature of questions in conditional probability.
Who is cheating?
problem

Who is cheating?

Age
14 to 16
Challenge level
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A practical experiment provides data. Moving onto expected results provides a context to establish the multiplication rule in probability, and an intuitive approach to conditional probability.
Prize Giving
problem

Prize Giving

Age
14 to 16
Challenge level
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What's the fairest way to choose 2 from 8 potential prize winners? How likely are you to be chosen?
The Wisdom of the Crowd
problem

The Wisdom of the Crowd

Age
11 to 16
Challenge level
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Who's closest to the correct number of sweets in a jar - an individual guess or the average of many individuals' guesses? Which average?
Capture and recapture
problem

Capture and recapture

Age
11 to 16
Challenge level
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How do scientists or mathematicians estimate the size of a population of wild animals?
How Confident Are You?
problem

How Confident Are You?

Age
11 to 16
Challenge level
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What proportion of people make 90% confident guesses which actually contain the correct answer?
Louis' Ice Cream Business
problem

Louis' Ice Cream Business

Age
14 to 16
Challenge level
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Should Louis go for the safer options, hoping to limit his losses, or would he be better off with a riskier strategy, focusing on maximising his profit?
To insure or not to insure
problem

To insure or not to insure

Age
14 to 16
Challenge level
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Should you insure your mobile phone? It rather depends on whether you focus on the long-term pay-off or the effect of a single event.

This is part of our Secondary Curriculum collection of favourite rich tasks arranged by topic.

Scroll down to see the complete collection, or explore our subcollections on Perimeter and Area in two dimensions, and Surface Area and Volume in three dimensions.

Odds and Evens
problem
Favourite

Odds and Evens

Age
11 to 14
Challenge level
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Are these games fair? How can you tell?
Interactive Spinners
problem
Favourite

Interactive Spinners

Age
11 to 14
Challenge level
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This interactivity invites you to make conjectures and explore probabilities of outcomes related to two independent events.
Sociable Cards
problem
Favourite

Sociable Cards

Age
11 to 14
Challenge level
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Move your counters through this snake of cards and see how far you can go. Are you surprised by where you end up?
Do you feel lucky?
problem
Favourite

Do you feel lucky?

Age
11 to 14
Challenge level
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Some people offer advice on how to win at games of chance, or how to influence probability in your favour. Can you decide whether advice is good or not?
What does random look like?
problem
Favourite

What does random look like?

Age
11 to 14
Challenge level
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Engage in a little mathematical detective work to see if you can spot the fakes.
At least one...
problem
Favourite

At least one...

Age
11 to 14
Challenge level
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Imagine flipping a coin a number of times. Can you work out the probability you will get a head on at least one of the flips?

Statistical shorts
problem
Favourite

Statistical shorts

Age
11 to 16
Challenge level
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Can you decide whether these short statistical statements are always, sometimes or never true?
Flippin' discs
problem
Favourite

Flippin' discs

Age
11 to 14
Challenge level
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Discs are flipped in the air. You win if all the faces show the same colour. What is the probability of winning?
Two's company
problem
Favourite

Two's company

Age
11 to 14
Challenge level
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Seven balls are shaken. You win if the two blue balls end up touching. What is the probability of winning?
Cosy corner
problem
Favourite

Cosy corner

Age
11 to 14
Challenge level
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Six balls are shaken. You win if at least one red ball ends in a corner. What is the probability of winning?
Non-Transitive Dice
problem
Favourite

Non-Transitive Dice

Age
11 to 14
Challenge level
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Alison and Charlie are playing a game. Charlie wants to go first so Alison lets him. Was that such a good idea?


Image
Probability - Stage 3 STEM footer
 

You may also be interested in this collection of activities from the STEM Learning website, that complement the NRICH activities above.

This is part of our Secondary Curriculum collection of favourite rich tasks arranged by topic.

Scroll down to see the complete collection, or explore our subcollections on Perimeter and Area in two dimensions, and Surface Area and Volume in three dimensions.

Chances are
problem
Favourite

Chances are

Age
14 to 16
Challenge level
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Which of these games would you play to give yourself the best possible chance of winning a prize?
The Better Choice
problem
Favourite

The Better Choice

Age
14 to 16
Challenge level
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Here are two games you can play. Which offers the better chance of winning?
Which spinners?
problem
Favourite

Which spinners?

Age
14 to 18
Challenge level
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Can you work out which spinners were used to generate the frequency charts?
Last one standing
problem
Favourite

Last one standing

Age
14 to 16
Challenge level
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Imagine a room full of people who keep flipping coins until they get a tail. Will anyone get six heads in a row?
Who's the winner?
problem
Favourite

Who's the winner?

Age
14 to 16
Challenge level
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When two closely matched teams play each other, what is the most likely result?
Same Number!
problem
Favourite

Same Number!

Age
14 to 16
Challenge level
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If everyone in your class picked a number from 1 to 225, do you think any two people would pick the same number?
Odds and Evens made fair
problem
Favourite

Odds and Evens made fair

Age
14 to 16
Challenge level
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In this follow-up to the problem Odds and Evens, we invite you to analyse a probability situation in order to find the general solution for a fair game.
In a box
problem
Favourite

In a box

Age
14 to 16
Challenge level
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Chris and Jo put two red and four blue ribbons in a box. They each pick a ribbon from the box without looking. Jo wins if the two ribbons are the same colour. Is the game fair?
Mathsland National Lottery
problem
Favourite

Mathsland National Lottery

Age
14 to 16
Challenge level
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Can you work out the probability of winning the Mathsland National Lottery?


Image
Probability - Stage 4 STEM footer
 

You may also be interested in this collection of activities from the STEM Learning website, that complement the NRICH activities above.