The following is the speech of "Comparison of Scores" in primary school mathematics, hoping to help everyone!
Lecture notes on score comparison
First of all, teaching materials
In the sixth book, the students have intuitively known the scores and initially learned some simple comparisons of the scores. But at that time, it was only limited to comparing the size of the same denominator score with the size of the different denominator score with the numerator of 1. Here we should further study the comparison of scores, and further deepen our understanding of scores through comparison.
Comparing the two scores, there are nothing more than the following three situations: first, the denominator is the same, but the numerator is different; Second, the numerator is the same, but the denominator is different; Third, numerator and denominator are different. Because the comparison of scores in the third case needs to master the basic nature and general scores, this part of the textbook only teaches the first two cases. The example 1 on page 365438 is the comparison of two fractions with the same denominator, and the example 2 on page 32 is the comparison of two fractions with the same numerator. Each example, on the one hand, compares the size of the score intuitively with the help of graphics, on the other hand, compares it with the score unit, and finally draws a conclusion and arranges corresponding exercises.
Second, preach the law.
1, situation introduction, stimulate interest
As the saying goes? Interest is the best teacher? With the interest in learning, students can actively participate in learning. Nengyi
Stones arouse thousands of waves, better stimulate students' strong interest in learning, and better lay a solid foundation for learning new knowledge. In order to stimulate their enthusiasm for learning and make students want to learn and like to learn, I use the story of pig eight quit sharing watermelon to introduce topics, stimulate their interest in learning and introduce new lessons.
2. Learn through communication
In the communication, students express their perceptual experience accumulated in comparing scores, so that everyone can clearly distinguish different types and methods of comparing scores. Through communication, students clarify the structure of knowledge, find a way to compare the same denominator with the same molecular fraction, activate thinking through communication and collision, and promote the cultivation of good qualities such as profundity and flexibility of thinking. In communication, students are active and open-minded, inspiring, encouraging and perfecting each other. Students really become the masters of learning.
2. Explore in guidance
Guide students to compare in observation and discussion by drawing pictures, finding score units and connecting with real life. So as to find a comparative method, which is verified in practice and application, thus confirming the conjecture. In this kind of teaching, teachers become the organizers, guides and collaborators of students' learning mathematics, and both teachers and students have experienced the pain and joy in the learning process.
Third, said the teaching process
Teaching objectives:
1, combined with specific scenes and intuitive operation, further understand the meaning of scores, experience the connection between the comparison of scores and life, and intuitively compare the sizes of scores with two numerators or denominators with examples and charts.
2. Mastering the method of comparing scores with denominator or numerator can solve related simple practical problems.
3. Help students feel the role of comparative classification, guessing and verification in solving problems, and gradually learn to solve problems in this way.
4. Infiltrate the mathematical thought of combining numbers and shapes, improve the ability of observation, operation, analysis and reasoning, and develop the sense of numbers.
Teaching emphasis: the method of comparing scores.
Teaching difficulty: the calculation of isomorphic fraction comparison
Review preparation
1, number of pictures: 1/3, 1/4, 3/5, 5/6, 5/8, 7/8.
These scores represent scores respectively.
(B) the introduction of new courses
1, the Monkey King and his apprentice went to the Western Heaven to learn Buddhist scriptures. One day, the Tang Priest felt hungry and asked the Monkey King and Pig to find something to eat. They found some fruits in the forest. The Monkey King said to Pig Bajie: We will give you 2/9 of the fruit, 2/7 to me and the rest to Master. Bajie smiled with satisfaction, and so did the Monkey King. Come on, class, who laughs smart? (Students try to answer)
2. Teachers talk about introducing new courses:
Teacher: Who laughs smart? You will understand after learning today's knowledge. Shall we study today? Score comparison?
(C) to carry out new courses
Second, explore new knowledge.
1, score classification
Teacher: Look at these scores just now. Can you classify them according to their characteristics?
Classify the blackboard books according to the students' answers:
The denominator is the same: 5/8, 7/8.
Molecular identity: 1/3, 1/4.
5 / 6,5 / 8
2. Explore the comparison method of scores with the same denominator.
(1) Students discuss the sizes of 5/8 and 7/8.
Feedback: A: Look at the picture to prove.
Answer: Please compare the fractional units.
(2) Compare your favorite methods: 3/4 and 1/4, 3/7 and 6/7.
(3) Teacher: By verifying these groups, you can find out how to compare scores with the same denominator.
Blackboard: The denominator is the same, and the bigger the numerator, the greater the score.
(4) Try to practice:
Answer: 3/9 and 7/9, 10/ 12 and12, 14/63 and 15.
B: Xiao Pang ran a race with Xiao Dingding. In five minutes, I ran 7/ 10 and trotted 8/ 10. Which of them runs faster? Why?
(5) Teacher's summary: Comparing two scores with the same denominator depends on the numerator, and the score with larger numerator is larger.
3. Explore the comparison method of the same molecular fraction.
The fractional comparison of (1) molecule is 1
Referee: Race with a small race. In five minutes, I ran 1/3 and trotted 1/4. Which of them runs faster? Why?
② Reading P32/ Rabbit: Use scores to represent the shaded parts in the picture below.
Comparison sizes: 1/5 and 1/7, 1/6 and 1/9, 1/7 and 1/8.
(3) After filling it out, tell me what you found.
Teacher: The more shares are divided equally, the smaller each share will be.
4 students give examples.
(2) Comparison of Fractions with Same Molecules
Teacher: The numerator is a fraction of 1, but the fraction with a large denominator is small. What about the numerator?
Students discuss the sizes of 5/6 and 5/8.
② Feedback:
Feedback: A: Look at the picture to prove.
A: By calculation.
Compare your favorite method: P33 Try it.
Teacher: What did you find?
Blackboard: The numerator is the same, but the score with the larger denominator is smaller.
⑤ Try to practice:
One, P33, practice.
B, explain? Who laughs smart?
(3) Teacher's summary
Third, consolidate the practice.
1, judgment: 4/9
2. Fill in the blanks:
( 1)5/ 12()9/ 12 1 1/23() 1 1/20 1() 14/ 19
(2) Xiao Pang can cross10m in July, and Xiao Pang can cross10m in June, and (3) the leap is even bigger.
(3) Mom and Dad took Xiaoya to eat pizza. Dad ate 4/8 pizzas, Mom ate 65,438+0/8 pizzas, Xiaoya ate 2/8 pizzas, and () ate the least.
*(4) 12 / 15,8 / 5,9 1/ 15 5 / 8,3 / 8,5 / 7
Fourth, class summary.
Teacher: What skills did you learn in this class? Is there a problem?
Student 1: Learn how to compare fractions with the same denominator or fractions with the same size.
Student 2: If you encounter a score with a different denominator and numerator, how do you compare it with the size?
Teacher: This classmate is really thoughtful and has raised a valuable question, which will be solved in future study. I also hope that students who are interested in this problem can use their brains and come up with solutions.
Fifth, practice independently
1, specific size
2/5 () 4/5115 ()/65438+1October 22nd 5/6 () 5/719 ()/kloc-.
2. Xiao Xiao and Xiao Ya spent 3/4 hours and 3/5 hours from school to the Science and Technology Museum respectively. () Fast. Because ()
3. What can I put in ()?
7/9 & lt； ()/9()>； 1/3 >()
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