"Ip dip sky blue! Who's 'it'? It's you!" Where would you position yourself so that you are 'it' if there are two players? Three players ...?
This challenge involves eight three-cube models made from interlocking cubes. Investigate different ways of putting the models together then compare your constructions.
What happens when you add the digits of a number then multiply the result by 2 and you keep doing this? You could try for different numbers and different rules.
When Charlie asked his grandmother how old she is, he didn't get a straightforward reply! Can you work out how old she is?
The challenge for you is to make a string of six (or more!) graded cubes.
How many different symmetrical shapes can you make by shading triangles or squares?
In this problem, we have created a pattern from smaller and smaller squares. If we carried on the pattern forever, what proportion of the image would be coloured blue?
Can you maximise the area available to a grazing goat?
Many of you worked out the rules behind these lights. Have a look at the solutions that were sent in.
Go to last month's problems to see more solutions.
In this article, read about the thinking behind the September 2010 secondary problems and why we hope they will be an excellent selection for a new academic year.
What are rich tasks and contexts and why do they matter?
This task depends on groups working collaboratively, discussing and reasoning to agree a final product.