You and at least one friend are going to explore the world. In this case, the world is a board containing 100 small file cards, arranged in a 10 x 10 grid. On each of these cards is a hidden math question. Shuffle them well and lay them face down on the board.

Flip a coin to decide who goes first. Each player then picks a card as home city from which to begin his voyage. The first player turns over his home card and then turns over an adjacent card. He must answer the question on that card correctly, so that he can leave it face up, get one point and move to that spot. If he gets the question wrong, he must turn the card face down again, remain where he is, and receive no points.

Then, the next player, too, turns over his starting card and an adjacent card. Once a card has been turned over and its question solved correctly, no other player can move into that space because it has already been discovered.

The goal is to gather as many points as possible by continuing to move around and around the board (or world). Be careful not to box yourself in. If you reach a dead end and there is no adjacent card for you to turn over, your voyage has come to an end. The other players continue to explore, gathering points until they, too, have explored as far as they can go. When everyone can no longer move, the player who has gathered the most points, wins.

Shuffle the cards, lay them out on the grid, and play again, this time tracing a new path around the world.

If you have lots of cardboard, you might like to try this game in your backyard, actually moving yourself onto the cards!