Anna has
A knight in chess moves in an "
Nine lightbulbs are arranged in a
Anna’s sister, Claire, has
All the squares of a
A rook in chess can move any number of squares in the same row or column. Let’s invent a new figure, a "little rook" that can only move one square in each of these directions. If we start with the "little rook" in the bottom right corner of an
There are
There are numbers
On a certain island there are
Sixteen lightbulbs are arranged in a