The concept of mathematics is abstract, but primary school students, especially those in lower grades, are in the stage of thinking mainly in images due to the limitations of age, knowledge and life. Knowing a thing and understanding a mathematical truth mainly depends on the specific image of the thing. Therefore, in the process of teaching mathematical concepts, teachers must be careful and patient, and try to introduce familiar contents in students' daily life. In this way, students' interest in learning will be high and their enthusiasm for thinking will be high. For example, when teaching average application problems, I use pencils as teaching AIDS to review the concept of "average score". I use nine small wooden blocks of the same size to make three piles, the first pile 1, the second pile 2 and the third pile 6. I asked, "Is there the same amount in each pile?" Which pile is more? Which pile is less? "Students can answer correctly. At this time, I mixed these three piles of wood together and divided them into three pieces, each of which was three pieces. I told the students that the new number "3" is the "average" of these three piles of wood blocks. I'll show you again. Let the students look carefully and think carefully: How did the "average" come from?