"Multiplying Decimals by Whole Numbers" Lecture Notes

As a selfless and dedicated teacher, it is inevitable to write lecture notes, which can help improve teachers’ theoretical literacy and ability to control teaching materials. How should we write lecture notes? Below is a sample lesson script for "Multiplying Decimals by Integers" that I carefully compiled for your reference. I hope it can help friends in need. "Multiplying decimals by whole numbers" Lesson Note 1

This section is the knowledge in the first section of the first unit of the fifth grade primary school mathematics volume. It enables students to understand the arithmetic of multiplying decimals by decimals and master the calculation method of multiplying decimals by integers. Be more proficient in written calculations. Multiplication of decimals is widely used in real life and mathematics learning. It is the basic knowledge and basic skills that primary school students should master and form. I just talked about the status of the first unit of knowledge in the textbook.

1. Teaching objectives

Achieve the following three goals by studying Examples 1 and 2 on the second and third pages of the textbook and doing and practicing questions 1~3 in 1 Teaching objectives.

1. Knowledge and skills: enable students to understand the meaning of decimals multiplied by integers and master the calculation rules of decimals multiplied by integers.

2. Process and method: Apply the change rule of product to calculate the multiplication of decimals by integers.

3. Emotional attitudes and values: Cultivate students’ good habits of being serious and careful, and experience the application of decimal multiplication in life.

2. Key points of teaching

Correctly perform the written calculation of decimals multiplied by integers, and calculate by using the relationship between rounded corners to convert decimals multiplied by integers into integers multiplied by integers. You can use the product change rule to calculate decimals multiplied by integers.

3. Difficulties in teaching and learning

1. Understand the meaning of multiplying a decimal by an integer.

2. The relationship between the number of decimal places in the product and the number of decimal places in the factors, and master the calculation method of multiplying decimals by integers.

3. On the basis of understanding the arithmetic and algorithms of decimal multiplication, master the decimal point position of the product in decimal multiplication.

IV. Analysis of academic situation

1. Before learning today’s content, students have mastered the multiplication and calculation methods of integers. However, due to the large class size, the teacher was unable to provide timely guidance. For students with learning difficulties, the students have not mastered the knowledge they have learned, so this class is designed to review integer multiplication.

2. The desire, ability and curiosity of fifth-grade students to seek knowledge have increased, and they have begun to think, pursue and explore new things. However, image thinking is dominant and requires hands-on operation. Understanding knowledge requires specific physical objects for support.

5. Preaching and Learning Methods

Based on the teaching content of this lesson and students’ thinking characteristics, as well as the new curriculum concept that students are the main body of learning, I plan to use the following methods Teaching and learning methods:

1. In teaching, I will create life situations of selling kites to arouse students' interest in learning mathematics and motivation for positive thinking, and guide students to actively explore.

2. Hands-on practice, active exploration, cooperation and communication are important ways for students to learn mathematics. Through hands-on operations, we discussed what is the difference between multiplying decimals by integers and multiplying integers? Fully reflect students' dominant position in teaching and fully mobilize students' enthusiasm and initiative for learning. Give students more space to carry out exploratory learning, allowing them to think independently in specific exercises and master the content they have learned.

3. Satisfy the intellectual curiosity of students at different levels and embody the principle of teaching students in accordance with their aptitude. Through "doing it", we can consolidate the calculation method of multiplying square decimals by integers and improve students' calculation ability.

4. Connect with life to solve problems around them, let students initially feel the close connection between mathematics and life, experience the application of mathematics, and promote students' development.

"Multiplying Decimals by Integers" Lecture Notes 2

1. Lecture Materials

"Multiplying Decimals by Integers" is taught on the basis of knowledge such as integer multiplication and the change rules of products. It also provides Later, you will learn knowledge such as multiplying decimals and dividing decimals as a preparation.

Based on the knowledge construction of the textbook and the students’ thinking characteristics, I determined that the teaching goal of this lesson is: to enable students to experience the process of converting decimals multiplied by integers into integers multiplied by integers, understand the transformation method, and be able to calculate correctly and Be able to provide appropriate explanations of the arithmetic involved. The teaching focus is to guide students to learn decimal multiplication using transformation methods. The difficulty in teaching is to guide students to understand arithmetic.

2. Preaching method

1. Situational teaching method

2. Inspirational questioning method

3. Combining learning and practice

3. Lecture method

1. Independent inquiry method

2. Contact with practice method

(How to teach to break through the teaching problems How to achieve the above goals? audio and video resources, self-made cards, small magnets, teachers’ infectious language, body movements, etc.) in order to hope that students can use existing knowledge and experience, connect with reality, explore independently, transfer analogies correctly, improve problem-solving abilities and develop The ability to innovate.)

4. Teaching design

According to the teaching reference and closely following the textbook, I make full use of the affinity of language, computer courseware and self-made cards and other material and non-material things. I use various methods to integrate various educational resources to arrange my teaching:

(1) Create situations and introduce excitement

At the beginning of the class, how can I quickly capture the students’ hearts and let them Will students quickly enter the classroom to learn? Einstein said: "Interest is the best teacher. "I fully explored the connotation of the theme map and created a purchasing activity before the Mingming family prepared to fly kites outdoors. I used emotional words to bring students into real life situations, so that students could feel immersed in the scene. Start with the familiar food purchase (intended to review integer multiplication and improve students' interest in learning), and then propose that Mingming's family is going to buy three magpie kites and ask students to help calculate how much it will cost, and ask students to discuss their ideas. At this time, students Emotions are high. The teacher asks the students to write down their thoughts first.

The teacher patrols, approaches the students, listens to them, helps students in difficulty, and harmonizes the relationship between teachers and students. When the relationship between students and teachers is further enhanced, they will naturally speak enthusiastically, eager to share their ideas with teachers and classmates, and actively participate in the process of buying kites. At this time, the only thing the teacher can do is. It is to happily share their wisdom with students, highlight the diversity of calculation strategies, and guide analysis and comparison to conclude that this method of converting decimals into integers is relatively simple. Students learned knowledge in a relaxed and happy atmosphere. "If it is." You, what would you buy? How many to buy? ***How ??much does it cost? "It pushed this purchase activity to a climax. The ideological education of students through the combination of learning and practice and scenario pictures is like spring rain moistening things silently.

(2) Independent exploration and discovery of rules

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1. Independent exploration

2. Reporting and communication

3. Summary method

When students experience success and build self-confidence, teachers The guide asked, "What we just solved are all about money. If it is not money, such as 0.72×5, how should we calculate it?" Can you use what you just learned to solve it? "One stone stirred up a thousand waves, and the students' curiosity and thirst for knowledge were mobilized again. With the encouragement of the teacher, in order to show their best selves in front of teachers and students, they actively engaged in effective thinking, explored and solved problems

Then ask students to fully display their ideas and complement each other to create sparks of thinking.

Finally, we were guided to get 0.72×5=3.6, and we deeply understood its arithmetic. That is to say, let students know what is happening and why it is happening. The teacher plays the role of "teaching people to fish is worse than teaching people to fish." On this basis, the teacher then guides the students to summarize and generalize the general method of multiplying decimals by whole numbers with the help of four ounces. Breaking through the difficult points will come naturally.

(3) Practical application, pioneering and innovation

"Mathematics comes from life and serves life." This is the fundamental purpose of guiding students to use the knowledge they have learned to solve practical problems. The exercises are designed from easy to difficult and expanded. The focus of each question is different. For example, the first question focuses on comparing the two calculation formulas in each group, so as to draw the difference between multiplying decimals by integers and multiplying integers by integers. At the same time, Understand how they are interconnected. The third question is a card question made by the teacher. It lists the problems that may arise when students calculate decimals multiplied by integers in vertical expressions. It requires students to make judgments and explain the reasons, which can attract students very well. Question 4 is the application of the rules discovered in Question 2, especially the last question. The answer is not unique, but is expandable and open to a certain extent, which can better cultivate students' divergent thinking.

(4) Summarize the whole lesson and talk about the results

Talking about the results in the summary can facilitate further communication between teachers and students and better sort out the knowledge learned. "Multiplying Decimals by Whole Numbers" Lecture Notes 3

1. Teaching Materials

Accurate understanding of the teaching materials is the prerequisite for a good class. "Multiplying Decimals by Whole Numbers" is the primary school mathematics fifth edition of Jiangsu Education The content of the fifth unit "Multiplying Decimals by Whole Numbers" in the first volume of grade 1. This lesson is about the calculation of numbers in primary school mathematics. Before studying this lesson, students have already learned the addition of decimals and the multiplication of integers. At the same time, the study of this lesson can pave the way for students to learn the calculation of multiplying decimals by decimals.

2. Talking about learning situation

A reasonable grasp of learning situation is the key to a good class. The perspective of modern teaching philosophy requires teachers to fully understand the students' situation. For students in the fifth grade of primary school, they already have a certain knowledge reserve and can establish connections between old and new knowledge under the guidance of teachers. At the same time, they still have the personality characteristics of difficulty concentrating. Therefore, flexible teaching methods should be adopted in the teaching process.

3. Teaching objectives

With a reasonable understanding of the teaching materials and academic situation, I have determined the following three-dimensional teaching objectives:

(1) Knowledge and Skills

Master the calculation method of decimals multiplied by integers, and be able to use vertical calculations to solve application problems of decimals multiplied by integers.

(2) Process and methods

Experience the process of exploring the calculation method of multiplying decimals by integers and improve your computing ability.

(3) Emotions, attitudes and values ??

In the process of exploring the calculation method of multiplying decimals by integers, feel the connection between mathematics and life and enhance number sense.

IV. The important and difficult points of teaching

With the teaching objectives established, and based on the teaching content, I determined that the teaching focus of this lesson is: the method of calculating decimals multiplied by integers in vertical columns. Because the more difficult thing to understand in vertical calculations is arithmetic, the teaching difficulty in this lesson is: the arithmetic in vertical calculations of multiplying decimals by integers.

5. Preaching and Learning

Tao Xingzhi once said: Living talent education is not about instilling knowledge, but about transferring the key to developing a cultural treasure house and doing everything we know. to students. Based on this, in order to break through key points, solve difficulties, and better achieve teaching goals. I combined the content characteristics of this lesson with the age characteristics of the students and adopted teaching methods such as explanation, practice and group discussion.

6. Talking about the teaching process

Now I will focus on my design of the teaching process.

(1) Introduction of new lessons

First of all, in the introduction process, I will display the schematic diagram of selling watermelon on the big screen, and ask: In summer, one kilogram of watermelon costs 0.8 yuan, and buying 3 kilograms of watermelon* **How ??much does it cost?

The topic of this lesson is "Multiplying Decimals by Integers" from the situational questions.

Using the introduction of situational questions about buying watermelons in life can make students feel the fact that mathematics comes from life, and can attract students' attention and draw students' thoughts from recess activities to classroom learning. Enhance students' interest in learning. This design is well in line with the personality and cognitive characteristics of primary school students.

(2) Exploration of new knowledge

Next, in the most important part of the exploration of new knowledge in teaching, I mainly design three teaching activities.

In the first teaching activity, students list the horizontal expressions. I will let the students try to solve this problem by themselves. By reviewing the addition of decimals they have learned before, it is not difficult for students to think of using the addition of decimals to add decimals. Three 0.8s are calculated by column addition and the result is 2.4.

Here I will further ask the students: Are there other ways to solve the problem?

Some students here will convert 0.8 yuan into 8 cents, and then calculate that they spent 28 cents, which is 2.4 yuan.

Then I will remind students that decimals can also be calculated using vertical expressions when multiplying integers. Here, students are asked to review the vertical calculation of integers multiplied by integers, and the vertical calculation method of 0.8 times 3 is explained to students. Through the explanation, students can understand the difficulty of this lesson: 3 times 8 tenths is 24 One tenth.

In this process, students can initially understand the vertical calculation method of multiplying decimals by integers. Using the conversion from yuan to angle, we can abstract the vertical calculation of 0.8 times 3 by using 3 times 8 tenths, and then calculate according to the vertical calculation method of integer multiplication, which is more conducive to students' acceptance.

In order to further derive the algorithm for vertical calculation of decimals multiplied by integers, I will design a second teaching activity and ask students: The price of watermelon increases in winter, one kilogram is 2.35 yuan, how much does it cost to buy 3 kilograms? Yuan? Let students try their own vertical calculations.

Here I would like to remind students: When calculating 0.8 times 3, you can use 3 times 8 tenths. What should you use 3 to times when calculating 2.35?

It is not difficult for students to imitate the vertical expression of 0.8 times 3 and write the vertical expression of 2.35 times 3 by themselves. Here I will emphasize to students that the multiplier 2.35 represents 235 hundredths.

Next is my third teaching activity, which is also the focus of this lesson. Ask the students: Use a calculator to calculate the three questions in the textbook, and think about the relationship between their multipliers and products? What did you find? And communicate with your deskmates.

Students can easily find that the number of decimal places in the first multiplier is the same as the number of decimal places in the product. Following the trend, my students and I summarized the vertical calculation method for decimals multiplied by integers: when multiplying decimals by integers, first calculate the product according to integer multiplication, and then point the decimal point. The multiplier has as many decimals as the product has, and the decimal points must be aligned. .

By calculating the results with a calculator and comparing the number of decimal places in products and factors, it is easier for students to think and communicate with their classmates to summarize the vertical calculation method of decimals multiplied by integers. This design can exercise students' ability to observe and summarize.

This concludes the three activities of exploring new knowledge. Based on their understanding of the algorithm of multiplying decimals by integers, students can easily derive the following vertical calculation method of multiplying decimals by decimals by analogy.

(3) Classroom exercises

To consolidate and improve this link.

Such exercises can deepen students’ impression of the vertical calculation algorithm for decimal multiplication of integers.

(4) Summary assignment

At the end of the course I will ask: What have you learned today?

Let students review: What is the algorithm for multiplying decimals by integers? What should we pay attention to during calculation?

In order to better consolidate the knowledge learned in this class, I will assign homework:

After class, I will come up with several formulas for multiplying decimals by integers and calculate them in vertical form. "Multiplying Decimals by Integers" Lecture Note 4

The content of my lecture is the content of the first information window of the eighth unit of multiplication of decimals in the first volume of the fourth grade primary school mathematics in Qingdao. Next, I will analyze the status of the teaching materials and the analysis of the learning situation, the objectives of the teaching, teaching methods, learning methods, and the teaching process.

1. Analysis of teaching material status and academic situation

Multiplying decimals by integers is taught on the basis that students have already learned multiplication of integers and addition and subtraction of decimals. Starting lesson. Before this, students have mastered knowledge such as the movement of the decimal point position and the changing rules of products. These are the knowledge base for students to understand and explore the arithmetic and calculation methods of decimal multiplication by integers. As a starting lesson, it is necessary to communicate the relationship between decimal multiplication and integer multiplication. While mastering calculation methods, it is also necessary to understand arithmetic. Understanding the arithmetic and calculation methods of multiplying decimals by integers is the key point; understanding the arithmetic is the difficulty; and the key is to fully use the idea of ??transformation to guide students to transform according to the changing rules of factors and products.

Before studying this lesson, students have already learned the meaning and properties of decimals, and will be taught based on the calculation process of decimal addition and subtraction and integer multiplication. If living learning scenarios are presented to students, some students can learn and master this new knowledge through the synthesis, transfer, and independent inquiry of knowledge. However, their mastery is usually fragmented and unsystematic, and some students may even fail to master it. Confused with the old knowledge of the past - such as the determination of the number of decimal places in the vertical expressions of decimal addition and subtraction, and the determination of the number of decimal places in the vertical expressions of decimal multiplication of integers.

2. Teaching objectives

1. Knowledge objectives: Combined with solving practical problems, learn the calculation method of decimal multiplication and be able to perform calculations correctly.

2. Skill goal: Experience the understanding of decimal multiplication of integers and the exploration of calculation methods, and experience the diversity of algorithms.

3. Emotional goals: In the process of solving practical problems, feel the great achievements of socialist construction, cultivate love for hometown and motherland, and stimulate students' interest in learning mathematics.

3. Preaching and Learning

How to overcome the difficulties and achieve the above three-dimensional goals? According to the characteristics of the teaching materials, this class uses multimedia as the main teaching method, and uses discussion, communication, and cooperative inquiry as the main teaching methods. Create situations in teaching, provide students with rich and intuitive observation materials, stimulate students' enthusiasm and initiative in learning, guide students to independently research and discover the meaning of decimal multiplication based on reviewing the meaning of integer multiplication, and use existing knowledge to solve problems The results of multiplying simple decimals by integers and applying them to solve practical problems.

The entire teaching is organized and carried out according to the following four links:

① Create situations and stimulate interest

② Collaborative exploration and understanding

③ Deepen application and consolidate new knowledge

④ Review the summary and ask questions.

Main learning method: transformation. There are also migrations, guesses-verifications, inductions.

Main teaching methods: leading and improving

IV. Teaching process

(1) Creating situations and stimulating introduction

In this link, I organized the teaching in two steps. The first is to create specific situations close to students' lives, narrow the distance between mathematical knowledge and real life, and enable students to realize the close connection between decimals and daily life. Therefore, when teaching, I first show the courseware: the picture of my boss today.

On the basis of student observation, ask "What is the content of the information presented above? What information did you get from it? What mathematical questions can you ask through this information?" Questions that students may ask after observation:

　 (1 ) How much is the water bill in August?

(2) How much is the electricity bill in August?

(The design intention is: raising a question is more important than solving a problem. Therefore, when using the Qingdao version of the textbook, I strive to cultivate students’ awareness and ability to ask questions.)

(2) *** Explore together and learn clearly

1. Explore the calculation method of multiplying decimals by integers

This link is the focus of this section of research, and it should be a breakthrough.

⑴First of all, who can answer the questions raised by the students above? How much is the water bill in August? Students can independently formulate equations, allowing students to understand the meaning of multiplying decimals by integers in a specific situation, which is the same as the meaning of multiplying integers.

⑵ Let go fully and give timely guidance. When guiding students to observe the calculation formula and find that a factor is a decimal? Students can be asked to engage in group discussions to find strategies for solving problems. Possible methods for students include: first, calculating by adding four 3.2s; second, converting 3.2 yuan into 32 cents, calculating 32 times 4 to get 128 cents, and then converting 128 cents into 12.8 cents. The third is to use vertical calculation. I focus on the vertical calculation method.

⑶ Pay attention to new knowledge and have a thorough understanding

Show various vertical algorithms. Ask questions to spark discussion among students and help them understand arithmetic. "How to convert it into the integer multiplication we have learned?" If the factor 3.2 is regarded as 32 and converted into integer multiplication, the product will be expanded to 10 times the original value. This is the change rule of the product. To get the original product, you need to reduce the multiplied product to 1/10 of its original value, so you should count one decimal point from the left of the product.

⑷Let students express calculation methods in their own language. First calculate by integer multiplication, and then determine the position of the decimal point according to the change rule of the product.

2. Expansion and application of the calculation method of decimals multiplied by integers

The second question is the one marked with the green dot. How much is the electricity bill in August? This can be completely left to students, and students should be asked to talk about the process of solving the problem to deepen their understanding of the calculation method.

(Design intention: In this link, students are first allowed to independently try to solve the calculation method of multiplying decimals by integers. Through communication, the teacher then guides students to focus on the vertical calculation method. During the calculation, Students understand arithmetic and calculate correctly.)

(3) Deepen application and consolidate new knowledge

In this link, I designed three sets of challenge questions. The first level is to add the decimal point to the product point of the multiplication vertical expression. This level is to consolidate the method of determining the number of decimal places in the product and allow students to tell the method of determining the position of the decimal point in the product. The second level is to do the calculations and see what you have discovered. The emphasis is on simplifying the calculation results based on the properties of decimals. The third level is to argue between right and wrong with a sharp eye. Students should be asked to explain the basis for their judgment, especially the handling of "0" in "2.48×60".

(Design intention: Through such breakthrough exercises, it not only mobilizes students' enthusiasm to participate in learning, but more importantly, allows students to understand the meaning of decimal multiplication and experience the use of decimal multiplication in a step-by-step practice from shallow to deep. The joy of solving practical problems.)

(4) Review the summary, ask questions, help students sort out and solve doubts.

In short, the design of this lesson is based on allowing students to actually feel, experience, comprehend, and think about the acquisition of new knowledge and establish mathematical models from classroom learning. The key to whether the effect can be achieved lies in how well the teacher pays attention to, grasps and regulates "generation" and "development" in the classroom.