juniper green
A mathematical game to test your knowledge of multiplication and division.
It was invented by a teacher in the UK at a school named Juniper Green.
That's why he called it Juniper Green. I learned about it from an article in Scientific American. The board consists of 100 rectangles labeled with the numbers from 1 to 100.
Two players take turns removing numbers according to certain rules. Two people can play against each other, or one can play against the computer. With two players, the computer will randomly choose who goes first.
Here are the rules:
 Each number selected must be a multiple or an exact divisor (factor) of the last number
the other player removed.
 The first number selected must be an even number.
 When there is no number left which satisfies rule 1, the player whose turn it is loses.
When it is your turn, pressing the help button will highlight the numbers which satisfy the rule.
