University of Cambridge
University of Cambridge: Nrich: Red Balloons, Blue Balloons
Use your problem solving skills to help Katie and Will solve the problem they have with blowing up their balloons until they pop. See if you can discover the solution on your own at this one page website. Then check the solution...
University of Cambridge
University of Cambridge: Nrich: Rectangle Tangle
On this one page website sharpen your logic and fractional part skills while working on this challenge. The solution is available to double check your solution.