Or search by topic
These two group activities use mathematical reasoning - one is numerical, one geometric.
What happens if you join every second point on this circle? How about every third point? Try with different steps and see if you can predict what will happen.
A number N is divisible by 10, 90, 98 and 882 but it is NOT divisible by 50 or 270 or 686 or 1764. It is also known that N is a factor of 9261000. What is N?