The use of functions is very important in programming. In the past more than 10 years of teaching programming courses, we found that students are not used to programming with functions. Teachers need to take some strategies to encourage students to develop the habit of programming with functions. This paper describes such a targeted strategy. This strategy contains three aspects: (1) Programming examples are designed, so as to teach students four opportunities to use functions; (2) the benefits of programming with functions are discussed, including better readability, maintainability, and reusability; (3) they are trained repeatedly in later programming exercises. The effect of this strategy has been verified by practice.