1, guide students to understand the meaning of reciprocal through observation, research, analogy and other mathematical activities, and summarize the methods of finding reciprocal;
2. Cultivate students' habit of cooperation and communication with others through mutual assistance activities;
3. Cultivate students' awareness of independent exploration and innovation through self-designed programs.
Emphasis and difficulty in teaching
Understand the meaning of reciprocal and master the method of finding reciprocal.
teaching tool
courseware
teaching process
First, the introduction of new courses.
Get down to business.
Second, the implementation of teaching
What do the students want to know about the countdown? Learn the meaning of reciprocal.
1, observe the example of 1 on page 24 of the textbook, and summarize the meaning of reciprocal.
3. Special numbers: 0 and 1 (lead the students to debate whether 0 has a reciprocal, and 1 has a reciprocal, what is it? )
The teacher summed up on the blackboard: 0 has no reciprocal, and the reciprocal of 1 is himself.
4. Learn Example 2- Method of Finding the Reciprocal Number
Let the students solve how to find the reciprocal of a number independently according to the knowledge they have learned, correct it collectively, summarize it by the teacher, and write down on the blackboard: the method of finding the reciprocal.
5. Feedback exercises
(1) Completed the 24-page textbook? Do it. ,
(2) Complete questions 2 and 3 in Exercise 6.
Third, classroom exercises.
Find out which two numbers are reciprocal.
Fourth, class summary.
After learning this lesson, we know that every number whose product is 1 will be reciprocal in the coming year. The reciprocal of 1 is itself, and 0 has no reciprocal.
Verb (short for verb) homework
Complete questions 1 and 4 in Exercise 6.
homework
Complete questions 1 and 4 in Exercise 6.
Mutual understanding of teaching plans (2) Teaching objectives
1, through practical activities such as experience, research and analogy, guide students to understand the meaning of reciprocal, let students experience the process of asking questions, exploring questions and applying knowledge, and independently summarize the method of finding reciprocal.
2. Cultivate students' habit of cooperation and communication through cooperative activities.
3. Cultivate students' awareness of independent learning and innovation through students' independent implementation of practical programs.
Emphasis and difficulty in teaching
Teaching emphasis: understanding the meaning of reciprocal and how to find reciprocal. Understand the meaning of reciprocal and master the method of finding reciprocal.
Teaching difficulty: mastering the method of finding the reciprocal.
teaching process
First, import
Courseware demonstration:
1, find the law: point to the answer.
2. Find out the rules, fill in the blanks and point out the students' answers.
3, oral calculation, driving a train.
Can you find out that the product of two numbers is 1? Theory pointing to life.
Shall we study together today? Countdown? See what secrets they have. Exhibition theme: understanding of reciprocity
Second, new funding.
1, the significance of teaching countdown.
(1) Students teach themselves, form discussion groups to conduct research, and then report to the whole class.
(2) Students report research results: What is reciprocal? Give an example to illustrate.
Two numbers whose product is 1 are reciprocal. Give examples. Show courseware
Look at each pair of numbers. What did you find?
How many pairs of logarithms whose product is 1 like this?
(3) Prompt students to clarify? Mutual? What do you mean? (reciprocal refers to the relationship between two numbers, which are interdependent, and a number cannot be called reciprocal)
(4) What are the characteristics of two reciprocal numbers?
What are the characteristics of each set of numbers like this?
The numerator and denominator of two numbers are reversed (the numerator and denominator of two numbers are just reversed)
2. Teach the method of finding the reciprocal. Try to write the reciprocal of 3/5 and 7/2.
(1) Write the reciprocal of 3/5: To find the reciprocal of a fraction, just switch the numerator (the number 3 flashes to the denominator of the fraction) and denominator (the number 5 flashes to the numerator of the fraction).
(2) Write the reciprocal of 7/52: To find the reciprocal of a fraction, just switch the numerator (the number 3 flashes to the denominator of the fraction) and the denominator (the number 5 flashes to the numerator of the fraction).
Thinking: Write the reciprocal of 6. Done independently.
Consider an integer as a fraction with a denominator of 1, and then exchange the positions of the numerator and denominator. six
= 6/ 1 1/6
To find the reciprocal of a number (except 0), just exchange the numerator and denominator of this number.
3. Special case of teaching,
Deep understanding
(1) 1 Is there a countdown? How to understand? (Because 1? 1= 1 According to? Two numbers whose product is 1 are reciprocal? So the reciprocal of 1 is 1. )
(2) Is there a countdown to 0? Why? (Because 0 multiplied by any number is not equal to 1, 0 has no reciprocal. )
4. Courseware demonstration and consolidation exercise: How to find the reciprocal of these numbers?
(1) Students answer independently and teachers patrol.
(2) When reporting, consciously let the students with learning difficulties talk about the method of countdown.
Third, consolidate the application
Courseware demonstration:
1, Exercise 6 Question 2: Fill in the blanks.
2. Find friends.
3. Write the reciprocal of the above figures.
4. Discrimination exercise: Exercise 6 Question 3? Really or not? .
5. My findings.
6, Ma Xiaohu diary, open training.
7. riddle:
Five four three two one
(Type a math noun)
Fourth, summary.
You already know? Countdown? What knowledge? What do you associate with it? What else do you want to know?