The self-taught genius would have turned 129 in December.
This problem about an infinite sum has a surprising answer.
This surprising result about 3D shapes tells us something deep about the nature of space.
Euler may not have cracked this problem completely, but it led to a lot of important work, including on what we today know as sudoku.
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.
Five favourite problems inspired by Leonhard Euler, one of the greatest mathematicians of all time.
Why did physicists at the beginning of the 20th century feel they needed a new — and strange — theory?
How to optimally fill a box with eight-dimensional oranges.
A new competition invites young people aged 11 to 19 to explore the history of maths for a chance to win cash prizes.