(Shanghai Higher Education Senior High School 3) Mathematics: 16.3 "Principle of Addition" Material 8. Principle of Addition [Question 1] Shanghai can go to Nanjing by train, plane or car. If there are 18 trains, 6 planes, and 20 cars every day. Q: How many different moves are there? Think: There are three types of methods from Shanghai to Nanjing, that is, you can take the train, you can take the plane, and you can take the car. There are 18 different options for taking the train, 6 for taking the plane, and 20 for taking the car. So there are 18 + 6 + 20 = 44 (species) different moves. Solution: 18 + 6 + 20 = 44 (species) Answer: There are 44 different moves.