First of all, talk about textbooks.
The arithmetic and simple algorithm part is to sort out and review the relevant knowledge learned. The commutative law of addition, associative law, multiplicative commutative law, associative law and distributive law are the basis of simple calculation in primary school mathematics, and also the basis of students' further study in the future. Therefore, I have set the following three teaching objectives.
1. Knowledge and skills: Through arrangement and review, students can form a certain knowledge network, master the operation rules systematically, and choose simple solutions according to the specific situation of the topic.
2. Process and method: Through arrangement, communication, cooperation and inquiry, we can experience the fun of inquiry, feel the value of mathematics, and cultivate students' consciousness of "learning and using mathematics".
3. Emotion and attitude: Stimulate students' positive emotional experience in learning simple calculation skills and forming simple calculation consciousness, intentionally cultivate students' simple calculation consciousness, and finally develop simple calculation habits.
Teaching emphasis: sorting out the operation rules.
Teaching difficulties: reasonable and flexible use of algorithms for simple calculations.
Second, talk about teaching methods and learning methods.
According to the content of teaching materials, teaching objectives and students' characteristics, on the basis of students' existing knowledge and experience, the teaching is organized with students' independent inquiry and arrangement as the main line, supplemented by discussion and exchange, so that students can complete their learning tasks in an open atmosphere.
Third, talk about the teaching process
This lesson is divided into four parts.
1. Inspire to get started and review old knowledge.
An interested teacher can only achieve certain goals by engaging in various activities with motivation and interest. So, at the beginning of the class, I threw out two questions: ① Do you want to know the age of the teacher? Do you want to know the telephone number of the teacher's home? Then tell the students with a smile: complete the following questions and you will have the answer.
The topic is as follows:
Stimulated by such an external factor, the enthusiasm of students will be very different with the same calculation.
2. Set up questions skillfully and organize independently
Completing the algorithm is the teaching focus of this course. In the process of reviewing. Students feel that they have learned a lot of algorithms and need to sort them out. So how to organize it? Students communicate after thinking, and combined with the results of students' communication, I designed several questions to guide students to cooperate independently: ① Can you tell us all the algorithms we have learned? Can you solve it? In what way can it be expressed? Can you make the finishing result into a study card? Under the guidance of questions, students actively think, take the initiative to explore, cooperate and communicate, and make the results into study cards. Through the comparison, appreciation and evaluation of these study cards, students can draw the conclusion that the operation rules can be divided into two categories according to the operation mode or three categories according to the meaning of the operation rules, and summarize the sorting method of expressing the operation rules by letters, which is concise and easy to understand and remember. Such a process of autonomous activities can make students realize that collation is a good learning method and can be used for reference in future knowledge collation.
3. Step by step, cultivate ability.
In math class, we often hear such a question: Teacher, do you want to use a simple method to calculate this problem? This shows that students' awareness of simple calculation is still very poor. Then, in the review class, how to cultivate students' awareness and habits of simple calculation and improve their simple calculation ability? I mainly start from the following aspects.
(1) After reading it, you can judge the question.
Students are often blind and random when calculating, and they are eager to calculate without seeing the questions clearly. So I first designed "reading" to make students read each question carefully. The topic is as follows:
The simple question is:
Then the students exchange: What do you think of the question just now? What have you been thinking? Through this link, students know that the premise of correctly using the algorithm is to learn to examine questions. At the same time, in the calculation, we should be good at observing the numerical characteristics and operation symbols in the problem, and think about how to use the operation rules reasonably to make the calculation simple. This not only avoids the blindness of calculation, but also cultivates the good habit of examining questions.
(2) Discuss it-reflect on it
Reflection is the source of discovery and an excellent way to train thinking, optimize thinking quality and promote knowledge assimilation and migration. So I consciously designed the topic that students are easy to make mistakes and confuse. The topic is as follows:
Discuss whether this calculation is reasonable among the students at the same table, and then reflect: Can you get any enlightenment from these questions? Still want to remind yourself of something? Enable students to find their own shortcomings, find the root causes and seek countermeasures, so as to avoid making mistakes again and further improve their computing ability.
(3) Can do it-can calculate.
The specific design of the purpose of the review project is a problem worthy of teachers' serious consideration. I try my best to design the exercises of this course, which is a challenge for students. The topic is as follows:
These questions can only be calculated correctly, quickly and reasonably by students doing and reviewing questions, observing formulas with holistic thinking, looking for characteristics and synthesizing various methods, and forming skilled operation skills.
(4) make up a series-it will be used.
In order to cultivate students' divergent thinking, I give students the right to give questions and let them design a problem that can be easily calculated as a primary teacher. The topic is as follows:
Requirements: Choose any number, just add "+","-",× "and" ∫ "to form a simple calculation problem, and test your deskmate.
4. Summarize and improve, and learn to learn.
Classroom is not only the main position for students to learn knowledge, but also the main position for students to learn to learn. Therefore, at the end of this class, I let students talk freely about their own gains and experiences, improve their cognitive level and lay the foundation for future study.
In the design of the whole class, I have carefully designed all the teaching links of students' independent inquiry and cooperative communication, so that students can learn actively and feel the benefits of arranging knowledge and the advantages of simple calculation, which not only achieves the purpose of arranging and reviewing, but also improves students' ability to use simple algorithms reasonably and flexibly.