For example, in the lesson "When did you meet?" (Teacher: Liang Ning, Huangchenggen Primary School, Xicheng District, Beijing), students are brought back with mathematical situations. In order to let students understand the relationship between time and measurement, the teacher showed a small ruler. Ask the students: Do you know this? What is this for? Energy time? Then show the courseware and circle the ruler. Ask the students: Is this the energy age? Let students realize that clocks and watches are also measuring tools, and feel the function of measurement initially.
(2) Mining the essence through the situation. Some mathematical contents can achieve good teaching effect directly through the creation of mathematical situations, so that students can explore and experience the essence independently in mathematical situations.
In the course of Cyclic Decimal taught by the Basic Teaching Research Center of the Academy of Educational Sciences, Mr. Wu created a mathematical situation for boys and girls to compete in calculation in groups. Boys' topic: (1) 21.305÷ 5 = _ _ (2) 70.7÷33 = _ _; The topic of girls' group: (1) 21.45 ÷15 = _ _ (2)10 ÷ 3 = _ _. In the teaching of circulating decimal, it is very important for students to experience circulation. Through the creation of mathematical situations, students will consciously discover the circulation phenomenon in the calculation process. The situation points to the essence and gives students the space to explore independently.
In the lesson "Prime Numbers and Composite Numbers" (taught by Li Ning, a primary school affiliated to Peking University), teachers create mathematical activity situations to let students clearly understand prime numbers and composite numbers in the operation process. The teacher provides students with a certain number of small square cardboard, so that students can make them into rectangles or squares. The teacher presented several numbers, 46, 25, 59, 32, 36, 5 1. Let the students choose a number as the number of small squares. The number of students' experience factors is the most important factor affecting the number of patchwork schemes in operation. In this process, the understanding of prime numbers and composite numbers is getting deeper and deeper.
(3) Arouse students' mathematics learning experience and think about new problems.
In the course of decimal addition and subtraction (teacher: Beijing Primary School, Ping Yu), decimal addition and subtraction are taught with the help of length units, and situations are created before class. The teacher said: The teacher has a soft ruler in his hand. Can you express its length in decimals? If the soft ruler is accidentally broken, how long is the remaining part?