Ivars Peterson's MathTrek
Pentominoes are flat shapes, or tiles, formed by joining together five unit squares. There are 12 different pentominoes.
This set of simple geometrical objects has inspired a variety of puzzles and games. The pentomino Web site, created by students of Belgian math teacher Odette De Meulemeester, provides all sorts of information about pentominoes, along with entertaining, challenging puzzles and a bimonthly competition.
The current competition brings together pentominoes and the addictive logic puzzle known as sudoku. See http://pentomino.wirisonline.net/recorde.html .
This sudoku variant requires a 10-by-10 grid and the digits 0 to 9. The grid itself is the only tiling of a square that consists of 10 F pentominoes and 10 V pentominoes. These tiles are combined in pairs to create new tiles made up of 10 connected squares. Given that numbers occupy some of the squares, the puzzle solver has to fill in the remaining squares with numbers so that each 10-square tile (decamino), row, and column contains the digits 0 to 9.
If you want to practice on some easier puzzles, you'll find links to five-by-five sudoku puzzles, each of which is made up of five pentominoes.
Peterson, I. 2006. A gathering for Gardner. MAA Online (March 27).
______. 2005. Sudoku math. MAA Online (June 20).
______. 2003. Pentomino battleships. MAA Online (Nov. 24).
Comments are welcome. Please send messages to Ivars Peterson at firstname.lastname@example.org.