Column

  1. Math

    Election Reversals

    By Ivars Peterson
  2. Math

    Goldbach Computations

    In 1742, historian and mathematician Christian Goldbach (1690–1764) wrote a letter to Leonhard Euler (1707–1783) in which he suggested, in effect, that every integer greater than 5 is the sum of three prime numbers. A prime number is evenly divisible only by itself and 1. Nowadays, Goldbach’s conjecture is expressed in the following equivalent form: […]

    By Ivars Peterson
  3. Math

    A Magic Knight’s Tour

    For as long as chessboards have existed, there have been puzzles involving chessboards and chess pieces. Some of the most enduring conundrums involve knights. Example of a knight’s tour in which the rows and columns have the same sum (260), but the diagonals add up to 348 and 168.