From the Super Mario Wiki
The player has to launch a ball (pinball-style, using the touch screen) into the field of play, where it will land in a numbered slot. This number will be crossed out on a bingo board. The object is to cross out as many numbers as possible. 100 points are scored for crossing out one number, and 500 points are added for crossing out a row of three in any direction. Crossing out every number earns 10,000 points. If the player completes a game with balls left over, 2000 points are scored for each ball. If a player completely crosses out the board with exactly nine of the 12 balls, he will earn the maximum score of 20,900.
 In-Game Instructions
Launch a ball into a numbered slot on the Touch Screen. That number will light up in the top screen. Get 3 numbers in a row to score!