Lesson 3

Explore

Have you ever played backgammon? Backgammon is a classic board game for two players consisting of a special board, dice, and pieces commonly called “checkers” or “stones.” The object of the game is to be the first player to move all of the checkers from their starting position on the board, around a track, and then off the board.

Before a player can begin clearing checkers off the board, the player must move all of the checkers to his or her home base, which is a quadrant of the backgammon board. In the photo the home base for the player in the bottom of the picture is the quadrant directly underneath that player’s outstretched arm. The home base for the player at the top of the picture is the quadrant directly below that player’s left hand. The majority of the game is spent moving checkers to the home base. The first player to move all of his or her checkers to the home base wins the game.

In this lesson you will determine the sums and differences of rational expressions. Just like in backgammon, you will discover that the actual adding and subtracting of expressions is easy—it’s the preparation of the expressions and meeting of certain conditions that can be a time challenge.