If you asked your mum/dad/friend to take you to the park today, what sort of response might you get?
The class were playing a maths game using interlocking cubes. Can you help them record what happened?
What can you say about the child who will be first on the playground tomorrow morning at breaktime in your school?
What statements can you make about the car that passes the school gates at 11am on Monday? How will you come up with statements and test your ideas?
You'll need to work in a group for this problem. The idea is to decide, as a group, whether you agree or disagree with each statement.
Try out the lottery that is played in a far-away land. What is the chance of winning?
Move your counters through this snake of cards and see how far you can go. Are you surprised by where you end up?
Engage in a little mathematical detective work to see if you can spot the fakes.
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?
Can you work out the probability of winning the Mathsland National Lottery? Try our simulator to test out your ideas.
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?
Imagine a room full of people who keep flipping coins until they get a tail. Will anyone get six heads in a row?
If everyone in your class picked a number from 1 to 225, do you think any two people would pick the same number?
The NRICH Stage 5 weekly challenges are shorter problems aimed at Post-16 students or enthusiastic younger students. There are 52 of them.
Mathmo is a revision tool for post-16 mathematics. It's great installed as a smartphone app, but it works well in pads and desktops and notebooks too. Give yourself a mathematical workout!
10 starting points for risk vs reward
Invent a set of three dice where each one is better than one of the others?
Explore these X-dice with numbers other than 1 to 6 on their faces. Which one is best?
Calculate probabilities associated with the Derren Brown coin scam in which he flipped 10 heads in a row.
Abi and Charlotte showed what good 'pattern sniffers' they are as they worked on this investigation.
There was some excellent conjecturing, proving and generalising that went on as you tackled this problem.
We received a variety of good strategies for solving this problem.
Lots of you noticed interesting patterns in the spreadsheet, and some went on to explain the patterns using algebra.
The beginnings of understanding probability begin much earlier than you might think...
All you need for this game is a pack of cards. While you play the game, think about strategies that will increase your chances of winning.
Uncertain about the likelihood of unexpected events? You are not alone!
This article explains how tree diagrams are constructed and helps you to understand how they can be used to calculate probabilities.
Use this animation to experiment with lotteries. Choose how many balls to match, how many are in the carousel, and how many draws to make at once.