Problems
Sorting Numbers
Stage: 1 Challenge Level: 
Use the interactivity to sort these numbers into sets. Can you give each set a name?
Shut the Box
Stage: 1 Challenge Level:
Try this old game that is very useful for so many arithmetical relationships.
Sorting Shapes
Stage: 1 Challenge Level:
This activity challenges you to make collections of shapes. Can you give your collection a name?
Birds in the Garden
Stage: 1 and 2 Challenge Level:
This activity asks you to collect information about the birds you see in the garden. Are there patterns in the data or do the birds seem to visit randomly?
Three Spinners
Stage: 2 Challenge Level:
These red, yellow and blue spinners were each spun 45 times in total. Can you work out which numbers are on each spinner?
How Random!
Stage: 2 Challenge Level:
Explore this interactivity and see if you can work out what it does. Could you use it to estimate the area of a shape?
Can't Find a Coin?
Stage: 3 Challenge Level:
Can you generate a set of random results? Can you fool the random simulator?
Misunderstanding Randomness
Stage: 3 Challenge Level:
Which of these ideas about randomness are actually correct?
Which Spinners?
Stage: 3 Challenge Level:
Which spinners were used to generate these frequency charts?
Data Matching
Stage: 4 Short Challenge Level:
Use your skill and judgement to match the sets of random data.
Coin Lines
Stage: 4 Challenge Level:
If a coin rolls and lands on a set of concentric circles what is the chance that the coin touches a line ?
Introducing Distributions
Stage: 4 Challenge Level:
When five dice are rolled together which do you expect to see more often, no sixes or all sixes ?
Distribution Differences
Stage: 4 Challenge Level:
How could you compare different situation where something random happens ? What sort of things might be the same ? What might be different ?
Random Inequalities
Stage: 5 Challenge Level:
Can you build a distribution with the maximum theoretical spread?
Scale Invariance
Stage: 5 Challenge Level:
By exploring the concept of scale invariance, find the probability that a random piece of real data begins with a 1.
Elsewhere...
Featured Solutions
Thousands and Millions
Those big numbers didn't seem to frighten you away. Take a look at how some of the problems were tackled.
Zin Obelisk
This was a popular problem. Many of you managed to make sense of all that jumbled up information.
Articles & Games
From A Random World to a Rational Universe
In the time before the mathematical idea of randomness was discovered, people thought that everything that happened was part of the will of supernatural beings. So have things changed?
Interactive Spinners
This interactivity invites you to make conjectures and explore probabilities of outcomes related to two independent events.
Quadruple Clue Sudoku
Four numbers on an intersection that need to be placed in the surrounding cells. That is all you need to know to solve this sudoku.
Distribution Maker
This tool allows you to create custom-specified random numbers, such as the total on three dice.
The Random World
Think that a coin toss is 50-50 heads or tails? Read on to appreciate the ever-changing and random nature of the world in which we live.
Randomness and Brownian Motion
In Classical times the Pythagorean philosophers believed that all things were made up from a specific number of tiny indivisible particles called ‘monads’. Each object contained a different number of particles, and so they believed that ‘everything was number’.
