In primary school mathematics, the practical problems with quantitative relations are described in language or words, and the problems formed in this way are called application problems. Let me sort out the application problems of multiplication in primary schools for your reference.

The first part: the application of fractional multiplication.

Teaching objectives 1. Understand and master the structure and solving method of the fractional application problem "What is the fraction of a number".

2. Infiltrate the corresponding ideas.

Teaching focus

Understand the relationship between the unit "1" in the application problem and the problem.

Teaching difficulties

1. Learn how to solve the application problem "What is the score of a number".

2. Correct and flexible judgment unit "1".

teaching process

First, review, question and introduce new ideas.

1. Say the meaning of, and rice.

2. Formula calculation

What is 20? How much is 6?

After the students have finished speaking, please tell them why these two questions are calculated by multiplication.

Dialogue 3: Students, as we know, what is the score of a given number? It is calculated by multiplication. This is multiplication.

What problems can the extension of the meaning of law solve? Today, we will study together (presentation topic: fractional application problem).

Second, exploration, questioning and understanding

(a) teaching examples 1 (can also be combined with students' actual self-editing)

The school bought 100 Jin of cabbage and ate it. How many kilograms did you eat?

1. Read the question, understand the meaning of the question, and know the known conditions and problems in the question; Find out the relationship between quantities.

2. analysis.

Teacher's question: Which sentence should we focus on? The sentence "eaten" is a fractional sentence. What does this mean?

That is, divide 100 kg of Chinese cabbage into 5 portions on average, and eat 4 portions like this.

3. draw pictures. (Demonstration courseware: Fractional Multiplication Application Problem 1)

Description of drawing: a. When the quantity is low and the rate is high, draw the unit "1" first.

B. ten copies, more than ten sketches.

C. draw with a ruler and pencil.

4. Try to answer.

Scheme 1: Do it with the learned integer multiplication.

(kg)

Solution 2:

5. Summary: Know what a number is and find its score. An application problem like this can be solved by multiplication according to the meaning of fractional multiplication.

(2) Consolidate exercises

There are 44 students in Class One, Grade Six, and the chorus takes up the whole class. How many people join the choir?

1. Which quantity is the unit "1"?

2. Why use multiplication?

(3) Teaching Example 2

Example 2. Xiao Lin's height is meters, Xiao Qiang's is Xiao Lin's, and Xiao Qiang's height is meters.

1. Demonstration courseware: Fractional multiplication application problem 2

Asking how many people join the choir is actually asking for food.

3. Formulation: (meter) fractional multiplication application problem

Xiao Qiang's height 100 meter.

(d) Different exercises

Xiao Qiang is 100 meter tall, and Kobayashi is twice as tall as Xiao Qiang. How tall is Kobayashi?

Third, induction and summary.

1. What do you want to calculate by multiplication?

2. What are the characteristics of the conditions and problems solved by fractional multiplication? Where to start the analysis?

* * * Similarity: both the unit "1" and the score are known. Find the fraction of the unit "1".

Analysis can start with scores.

Fourth, training and deepening.

(A) first analyze the quantitative relationship, and then list the answers.

1. A duck weighs 100 kg, and the weight of a chicken is 20 kg of a duck. How much does this chicken weigh?

2. The price of a volleyball is 36 yuan, and the price of a basketball is the price of a volleyball. How much is a basketball?

(B) to improve the problem

1. A barrel of oil is 400 kilograms. How many kilograms did you use? How many kilograms are left?

A barrel of oil is 400kg. How many kilograms does it need? How many kilograms are left?

Verb (abbreviation for verb) homework after class

(1) The road team planned to build a 4 km road, which has been repaired. How many kilometers have you built?

(2) A whale is 7 meters long, and the head occupies it. How long is the whale's head?

(3) The total length of chengdu-kunming railway is1100km, and bridges and tunnels account for about the total length. How many kilometers are the bridges and tunnels?

Chapter two: multiplication application problems

Teaching objectives

1, can analyze the relationship between simple application problems of multiplication.

2. Cultivate students' abilities of observation, analysis, comparison and language expression.

Teaching preparation

Some CDs.

teaching process

First, create scenarios and introduce activities.

1, Teacher: Children, it's June Day. Everyone planted many flowers to decorate the classroom. Let's see what flowers are planted. The courseware shows that a basket contains some blue flowers, red flowers and yellow flowers.

Everyone stood up and counted the number of each flower.

It shows that there are two red flowers, four yellow flowers and three two flowers from blue.

2. Understanding: There are two blue flowers and four red flowers. We say that the number of red flowers is four times that of blue flowers, and three yellow flowers are two. How can we say that? (Answer by name)

Step 3: Swing

Students take out small pictures. (1) The first row needs two disks, and the number of disks in the second row is three times that in the first row.

Q: The number of discs in the second row is three times that in the first row. How many disks are there in the second row? How do you take pictures?

Blackboard book: 3 2× 3 = 6

(2) The first row is required to have three wafers, and the second row is four times the size of the first row.

Discuss together: how to say it? How is it placed?

Second, cooperative exploration, building new knowledge

1. Look, there are two blue flowers. The number of yellow flowers is three times that of blue flowers. Can you tell how many yellow flowers there are? what do you think? (Discuss in groups of four)

Communication: The number of yellow flowers is 3 times that of blue flowers, and the number of yellow flowers is 2×3=6, so there are 6 yellow flowers.

2. Think about it: How many times are red flowers more than blue flowers? How many red flowers are there?

(Talk to each other in the group) List the formula: 2×4=8.

3. Summary: As can be seen from the above, what is the multiple of a number? Is to find the sum of these numbers, so we have to use multiplication to calculate.

Third, apply forms and lines to strengthen practice.

1, page 82 of the textbook, page 83 "Think and do" 1 and 2, look at the pictures, understand the meaning and fill in the blanks. Students do it independently.

2, the third question, the students are posing, posing.

3, the game, change butterflies (make the fifth question a headdress, students choose according to the topic)

4 times of 5, 3 times of 5×4 2, 2×3.

3, 4, 3, 3, 4, 2, 4.

Fourth, self-evaluation to deepen understanding.

What did we learn in this class? Are you satisfied with your study?

Verb (abbreviation for verb) class assignment

Chapter 3: The application of fractional multiplication.

Teaching objectives

1. Further master the quantitative relationship of fractional multiplication application problems.

2. Learn to use the meaning of multiplying a number by a fraction to solve the application problem of two-step fractional multiplication.

Teaching focus

1. Master the ideas and methods of solving two-step fractional application problems.

2. The ability to draw line segments and analyze application problems.

Teaching difficulties

Analyze the difference between two units "1".

teaching process

First, review, question and introduce new ideas.

(1) indicates the unit "1" in the following rate sentence.

1.b is a.

Xiaohong is Xiao Ming's height.

The students who take part in the chorus account for the whole class.

4.b is equivalent to a.

1The price of basketball is twice that of a volleyball.

(b) Oral analysis of parallel answers

1. There is 18 yuan in Xiao Liang's savings box. The money saved by Xiaohua belongs to Xiao Liang. How much did Xiaohua save?

2. Xiaohua saved 15 yuan, and Xiao Xin saved Xiaohua's. How much did Xiao Xin save?

(3) Introduction: The students have successfully completed the two questions just reviewed. Now, will you answer these two small questions into one question? This is the new content to be learned in this class.

(Presentation topic-application of scores)

Second, explore and understand.

(a) Show examples of group editing.

Example 2. Liang Xiao has 18 yuan in his savings box. The money saved by Xiaohua belongs to Liang Xiao, and that of Xiao Xin belongs to Xiaohua. How much did Xiao Xin save?

1. Thinking and discussion

(1) What do you mean by Xiaohua's savings? Who is this unit "1"?

(2) What does Xiao Xin Xiaohua's money mean? Who is this unit "1"?

2. Reporting ideas and methods

According to "the money saved by Xiaohua belongs to Xiao Liang" and taking Liang Xiaocun's money as the unit "1", we can find out the money saved by Xiaohua. According to "Xiao Xin's money belongs to Xiaohua", we take Xiaohua's money as the unit "1", and then mark Xiao Xin's savings:.

On this basis, try to list the comprehensive formula:

(2) Consolidate exercises

Xiaohua has 36 stamps, Xiao Xin's stamps are Xiaohua's, and Xiaoming's stamps are Xiao Xin's. How many stamps does Xiaoming have?

1. Analyze the quantitative relationship and get the parallel solution independently.

2. Students perform on the blackboard.

(Zhang)

(Zhang)

Xiaoming has 40.

3. Comprehensive formula

Third, induction and understanding.

What are the characteristics of the problem solved by multiplication? ""What is the way to solve the problem? "

1. Read the questions carefully and find out the conditions and problems.

2. Determine the exact quantitative relationship of the unit "1"

According to the meaning of fractional multiplication, find out the corresponding relationship between quantity and rate, that is, who is whose score.

3. Column solution

Blackboard writing: Grasp the fractional sentences and find the correct unit "1".

Draw a picture to analyze, and there is no hurry.

Fourth, training and deepening.

According to each sentence below, what can you think of?

1. The number of apples is pears. (For example, pear is "1"; Eat less apples and more pears; There are fewer apples than pears. )

2. Full-length repair

The price is lower now than before.

(2) Analyze the quantitative relationship orally first, and then give detailed answers.

1. The incubation period of geese, ducks and chickens is 30 days. How many days is the incubation period of chicken?

2.3 Students jump rope, Xiaoming jumped 120 times, Xiao Qiang jumped Xiaoming's, Liang Xiao jumped twice as much as Xiao Qiang, and Liang Xiao jumped how many times?

(3) Improve the questions.

There are three classes in grade six who take part in tree planting, _ _ _ _ _ _ _ _. The number of trees planted in Class Two is one, and the number of trees planted in Class Three is twice that of Class Two. _ _ _ _ _ _ _ _ _ _?

Verb (abbreviation for verb) homework after class

(1) Grade 6 students collect 180 cans, of which one class collects and the other class collects. How many cans were collected in each class?

(2) Long-distance running exercise: running 3 kilometers, running the same as Xiao Gang and running the same as a bear. How many kilometers did Xiao Gang and Xiao Yong run?

Sixth, blackboard design

Application of fractional multiplication

Liang Xiao's savings box contains 18 yuan, Xiaohua's savings are Liang Xiao's and Xiao Xin's savings are Xiaohua's. How much did Xiao Xin save?

Comments on teaching plans:

The key to solving the fractional application problem is to find out the quantitative relationship in the problem, who compares with whom, who is regarded as the unit "1" for whose score, the fractional multiplication application problem, and the elementary school mathematics teaching plan "fractional multiplication application problem". This is also the focus and difficulty of classroom teaching and the embodiment of students' analytical ability. This is one of the goals of our class.

This lesson is the second part of the application of fractions. Students have the ability to preliminarily analyze what is known and find the unit "1", but a condition and a quantity are added. It is necessary to make use of the existing analysis methods and analyze them step by step, so as to make it easier. Using the form of group cooperation in teaching, giving full play to collective wisdom and understanding the known conditions in discussion will help students to eliminate thinking obstacles. Teachers should use line graphs to deepen students' understanding of topics, so as to realize the transfer and leap from old knowledge to new knowledge. The design of exercises, from easy to difficult, changes the conditions, which helps students to analyze flexibly and prevent stereotypes.

;