Keep your finger on the clock so that you can have it count down when the ball is in play. Let the clock remain in motion until the ball goes out of bounds, a time-out has been called or the referee has indicated that a foul has been called or a violation has been committed.
Keep track of each team's running score. As the game goes on, you are responsible for putting field goals, 3-point field goals and free throws on the scoreboard. When a 3-point shot has been attempted, the referee will display three fingers for your benefit. However, if you have not seen his fingers and you can't tell whether the shot came from behind the line or in front of it, you must call him over to avoid a discrepancy.
Make sure all players check in with you when they are coming off the bench and into the game. Players who do not check in with the score clock operator are in the game illegally. If this happens, you must let the referee know.
Keep track of fouls that each player has on the score clock. Players are allowed five or six fouls, depending on the level of play, and when they exceed those totals they must come out of the game. You must let the referee know when a player has fouled out.
Keep track of team fouls. When a team goes over the limit of fouls for a quarter (high school or professional) or a half (college), the opposing team will get bonus free throws. You have to make sure the referee knows if a team has exceeded its foul limit. In college basketball, non-shooting fouls result in one free throw and a bonus free throw if the first free throw is successful after the seventh team foul. After the tenth team foul, non-shooting fouls result in two free throws. You must point this out to the official.