The content of this unit includes: the understanding of perimeter, the measurement and calculation of perimeter, the calculation method of rectangle and square perimeter, transportation and mathematics. What is perimeter is the first lesson in this unit. It is based on students' understanding of plane graphics such as triangle, parallelogram, rectangle and square, and learning the perimeter of plane graphics. Through this part of the teaching, students can initially perceive the meaning of perimeter, paving the way for understanding the perimeter and its calculation of various graphics in the future.
2. Teaching objectives
The new curriculum standard points out that through mathematics learning, students can acquire necessary and important mathematics knowledge, basic mathematical thinking methods and necessary application skills to adapt to future social life and further development. Combined with the characteristics of teaching materials and the actual level and psychological characteristics of junior three students, I have determined the following teaching objectives:
(1) cognitive goal
Know the meaning of perimeter and establish the concept of perimeter.
(2) Ability goal: Combining with specific objects, we can know the surroundings through activities such as observation and operation. Can initially measure the perimeter of triangles, quadrangles and other graphics.
(3) Emotional goal: Stimulate students' interest in learning through demonstration operation, cultivate students' habit of observation and thinking, and enable students to achieve the purpose of autonomous learning, participation in learning and cooperative learning.
(4) Innovation goal: On the basis of students' full participation in the learning process, cultivate and develop students' multi-directional thinking, and encourage students to measure and calculate the perimeter of graphics in various ways.
4. Teaching emphases and difficulties.
Know the perimeter, understand the meaning of perimeter, and develop the concept of space.