In the middle and lower grades of primary school, I have been able to understand the meaning of fractions, read and write simple fractions, compare two fractions or fractions with the same denominator, and solve some basic practical problems that a fraction or a whole fraction is several objects.

② Main contents:

The meaning of 1. score

2. True score and false score

3. Find out that one number is a fraction of another.

4. The relationship between fraction and division

5. False scores are converted into integers or with scores.

6. Mutualization of Fractions and Decimals

(3) learning objectives:

1. Understand the meaning of unit "1" and fractional unit initially, and further understand the meaning of fraction;

2. Explore and understand the relationship between fraction and division, express the conversion result of measurement unit with fraction, and find out the practical problem that one number is the fraction of another number;

3. Knowing the true fraction and the false fraction, knowing that the decimal part is a combination of integer and true fraction, will turn the false fraction into an integer or decimal part, and will make the decimal part and the decimal part reciprocal;

4. Further develop the sense of numbers in learning and cultivate the ability of observation, comparison, abstraction and generalization;

5. Understand the application of fractions in daily life, enhance the awareness of independent exploration and cooperation, and establish confidence in learning mathematics well.

(4) Learning methods:

1. Based on the existing cognitive scores, the average objects are felt to be very extensive, thus the concept of unit "1" is abstracted, which reflects the process from concrete to abstract, and the generation of perceptual scores is the inevitable result of integer development;

2. Combine numbers with shapes, learn the knowledge of fractions, and further enrich the understanding of false fractions by coloring in the graphs; With the help of intuitive graphics and the meaning of fraction, this paper explores and understands the practical problem of how to get a fraction from one number to another.

3. Deepen the understanding of music score knowledge in operation activities, such as using coloring and tracing points to represent music score, so as to better understand the meaning of music score; Understand the internal relationship between false score and true score in coloring activities; Explore and understand the relationship between fraction and division by dividing paper, and constantly improve your thinking level through intuitive thinking.

(5) learning focus:

1. Understand the meaning of the score and the unit "1";

2. Understand the meaning of true score and false score, and find out the practical significance and problem-solving ideas of how much one number is another;

3. Understanding and mastering the relationship between fractions and division will turn false fractions into integers or fractions;

4. Master the reciprocal method of fractions and decimals.

(6) Difficulties:

1. Grasp the meaning and unit of the score.

The concept of the meaning of a fraction is not difficult. The key is to abstract the unit "1". When learning, we need to know what each score is divided into equal parts, so we know that an object, a unit of measurement or a whole composed of many objects can be expressed by a natural number 1, which is commonly called the unit "1". On the basis of combining the meaning of fraction, we understand the number representing one of them, which is called fraction unit.

2. Distinguish between true score and false score:

Based on the understanding of fractional units, we feel that some fractional molecules are larger than the denominator, some fractional molecules are smaller than the denominator, and some fractional molecules are equal to the denominator through coloring operation. After these comparative classification processes, the concepts of true score and false score are further clarified.

True fraction: the fraction whose numerator is smaller than the denominator.

False fraction: a fraction whose numerator is greater than the denominator or whose numerator and denominator are equal.

3. Solve the practical problem that one number is a fraction of another number:

With the help of intuitive graphics and the meaning of fraction, this paper explores and understands the practical problem of how to get a fraction from one number to another. The key is to find out which quantity is the unit of average score "1".

4. Understand the relationship between fraction and division

After showing the specific situation, the division formula is listed according to the meaning of division, and then with the help of intuitive hands-on operation and life experience, it is clear that the result can be expressed by a fraction, and it is concluded that a÷b= ab. In integer division, if the divisor cannot be 0, the denominator in the fraction is not 0, obviously b ≠ 0; At the same time, when converting false fractions into integers or fractions, we can explore the conversion method by understanding the relationship between fractions and division.

5. Mutualization of Fractions and Decimals

Through the comparison of fractions and decimals, it is naturally recognized that fractions and decimals need to be converted into a unified unit of measurement for comparison. In most cases, it is more convenient to convert fractions into decimals. When there are endless situations, reserve digits according to the requirements of the topic. If there is no clear number in the title, two decimal places are generally reserved. When the arrangement is large or small, it can be unified into decimal comparison on the draft paper first, and finally sorted and compared with the original data.