Can you move a knight on a chessboard so that it visits every square exactly once? Euler was one of the first to analyse this problem systematically, but some questions about it are still open today.

Can you find a path through on this city map that crosses every bridge exactly once? Euler's answer to this problem started off the filed of graph theory.

Sara Zahedi has won a prestigious prize at the European Congress of Maths. Your future medical diagnoses, and even the welfare of sea life, may depend on her work.