Which times on a digital clock have a line of symmetry? Which look
the same upside-down? You might like to try this investigation and
What are the coordinates of this shape after it has been
transformed in the ways described? Compare these with the original
coordinates. What do you notice about the numbers?
These clocks have been reflected in a mirror. What times do they
These games were invented by Solomon W. Golomb, who came up with the idea of polyominoes.
For 2, 3 or 4 players
You will need:
To be last person to be able to place a pentomino piece on the playing board.
To prevent your opponent(s) from finding space to place pentomino pieces on the board.
To prepare for play:
See Bernard's Bag for a link to the complete set of pentomino shapes
The second version of the game requires players to use and develop their visual perception skills. Rather than rely on chance, as in the first game, players have to determine whether shapes held by their opponents will fill the spaces and which of their own pieces will alter the available spaces sufficiently to prevent play.
Computer Version (2 Players)