
Can you guess the colours of the 10 marbles in the bag? Can you develop an effective strategy for reaching 1000 points in the least number of rounds?

What happens to the perimeter of triangle ABC as the two smaller circles change size and roll around inside the bigger circle?

Can you decode the mysterious markings on this ancient bone tool?

Points D, E and F are on the the sides of triangle ABC. Circumcircles are drawn to the triangles ADE, BEF and CFD respectively. What do you notice about these three circumcircles?

Can you make a hypothesis to explain these ancient numbers?

I need a figure for the fish population in a lake, how does it help to catch and mark 40 fish ?

What information helped medical pioneers decide on the cause of a disease? Especially in a time before microscopes were as powerful as they are today ?

in how many ways can you place the numbers 1, 2, 3 … 9 in the nine regions of the Olympic Emblem (5 overlapping circles) so that the amount in each ring is the same?

A killer lion is causing devastation. From the locations of its reported activity, can you work out where its lair is located?


The circumcentres of four triangles are joined to form a quadrilateral. What do you notice about this quadrilateral as the dynamic image changes? Can you prove your conjecture?
A good visualisation can be really useful when we need to convince ourselves that a probability calculation is correct. Here's a nice one.
From the information you are asked to work out where the picture was taken. Is there too much information? How accurate can your answer be?
The puzzle can be solved by finding the values of the unknown digits (all indicated by asterisks) in the squares of the $9\times9$ grid.