Visualising and representing

Where should you start, if you want to finish back where you started?

Surprising numerical patterns can be explained using algebra and diagrams...

If you know the perimeter of a right angled triangle, what can you say about the area?

Which armies can be arranged in hollow square fighting formations?

Just because a problem is impossible doesn't mean it's difficult...

By selecting digits for an addition grid, what targets can you make?

What's special about the area of quadrilaterals drawn in a square?

What two-digit numbers can you make with these two dice? What can't you make?

Weekly Problem 34 - 2015
Four tiles are given. For which of them can three be placed together to form an equilateral triangle?

Weekly Problem 37 - 2014
Which of the five diagrams below could be drawn without taking the pen off the page and without drawing along a line already drawn?