Unit 1, Cognitive Multiplication

First, teaching material analysis:

On the basis that students have mastered simple addition and subtraction, this unit teaches multiplication, with emphasis on its significance. The whole unit includes two examples, two "attempts", one "thinking and doing" and exercise one. Textbook arrangement has the following characteristics:

1, strengthen the understanding and calculation of addition with the same number, and make full preparations for the preliminary understanding of multiplication. Multiplication and addition are closely related, and mastering addition can let you continue to learn multiplication. In addition, students are familiar with the addition of two numbers and the addition of three different numbers. Add up the same numbers, because there is less contact and it is unfamiliar. Therefore, before teaching multiplication, the textbook should strengthen the perceptual knowledge of adding several identical numbers, improve students' ability to calculate adding several identical numbers, and lay a solid foundation for learning multiplication.

2. Let students fully understand the meaning of multiplication. Multiplication is a simple operation, which can find the sum of several identical addends. The textbook does not mechanically instill the meaning of multiplication in students, but allows students to solve the practical problem of finding the sum of several identical addends by addition and multiplication, from which they can understand the meaning of multiplication and feel its two main connotations: multiplication can only be used when several identical numbers are added, and column multiplication is often simpler than addition.

3. Combine the understanding of the meaning of multiplication with the application of multiplication to solve practical problems, and optimize the process of concept formation. The meaning of multiplication belongs to the concept of operation. The general process of primary school students' concept formation is "accumulating perceptual knowledge about concepts in practical activities → processing perceptual knowledge into representations or abstracting it into concepts → applying concepts in practice to further expand concepts", which shows that the formation of concepts has always been linked with practical problems. This unit textbook has changed the content structure of teaching multiplication meaning first and then multiplication application problems in previous mathematics textbooks. From the example with the meaning of multiplication, the concepts of formation and application are integrated.

Second, the teaching objectives:

1, so that the student manager can express the addition of several identical numbers as the formation process of multiplication formula, and initially understand the meaning of multiplication and the relationship and difference between multiplication and addition; Can write and read multiplication formula correctly, and know the names of each part in the formula; Calculates the product of multiplication and addition.

2. Make students learn how to abstract several mathematical problems from simple actual situations, and list multiplication formulas according to the mathematical problems, so as to cultivate the habit of orderly thinking and improve problem-solving ability.

3. Make students further cultivate their interest in learning mathematics and cooperative learning attitude in the process of preliminary understanding and application of multiplication.

Third, the importance and difficulty of teaching

1. key: understand the meaning of multiplication.

2. Difficulties: I have a preliminary understanding of the relationship and difference between multiplication and addition.

The first lesson is to know multiplication.

Teaching content: Page 65438 +0-3 of the textbook.

Teaching purpose: to make students know the symbols of multiplication, know the meaning of multiplication, master the reading methods and formulas of multiplication, know the names of various parts of multiplication formula, and cultivate students' preliminary ability of analysis, synthesis, abstraction and generalization.

Teaching preparation: learning tools

Teaching process:

The teacher is very active.

Learn to take the initiative

First, the introduction of new courses.

We learned addition and subtraction. Starting today, we will learn a new algorithm, which is multiplication. In this lesson, let's learn the preliminary understanding of multiplication first. (Title on the blackboard: Understanding multiplication)

Reading theme

Second, new funding.

1, teaching example 1.

(1) Draw an example of 1

(2) Question: How many places in the picture are there white rabbits? How many are there in each place? How many are there in a * * * 2? How many white rabbits are there?

Blackboard: 2+2+2=6 (only)

How many places in the picture have chickens? How many are there in each place? How many 3s does a * * * have? How many chickens are there in a box? How to calculate?

Blackboard: 3+3+3 = 12 (only)

(3) The teacher pointed to the formula and asked:

What are the addends in these two formulas? How much does it add up to? how much is it?

(4) Summary: How many rabbits are there? That is, how much is three, two and one * * *, which can be calculated by adding. Find the number of chickens * * *, that is, what is four and three * * *, and four and three can be calculated by adding them together.

2, teaching "give it a try"

(1) Give it a try.

(2) Example 1, Question: How many are there in each line? How many rows are there? How many * * s are there in Qiu Yi? How to calculate? To find a root of * * * is to find the sum of several.

(3) Example 2, Question: Looking horizontally, how many are there in each row? How many rows are there? How many * * s are there in Qiu Yi? How to calculate? To find a root of * * * is to find the sum of several.

(4) Students fill in the book, complete the "try it" and concentrate on communication.

3. Teaching Example 2

(1) shows the diagram of Example 2.

(2) Can you find out how many computers are in a * *? (blackboard writing: 2+2+2+2=8)

2+2+2+2=8, which means how much do you get when you add it up?

(3) The teacher explained that four twos add up to eight, which can also be calculated by a multiplier and can be written as 2×4=8. Expressions such as 2×4=8 are multiplication expressions. This symbol ("refers to ×") is called multiplication sign (blackboard writing: multiplication sign) and can be written like this (demonstration writing "×").

(4) Four twos add up to 8, which can be written not only as 2×4=8, but also as 4×2=8. Who can read this formula?

The multiplication formula is the same as the addition formula, and each part has a name. Who will talk about the names of the parts of the addition formula first?

Students answer the teacher's blackboard: 2+2+2+2 = 8.

(addendum) (addendum) (addendum) (addendum) (and)

The teacher explained: in the multiplication formula, the number before the equal sign is called the multiplier, and the number after the equal sign is called the product.

Blackboard: 4 × 2 = 8

(Multiplier) (Multiplier) (Product)

Students at the same table talk to each other about the names of the parts in the multiplication formula.

Who can tell me the names of the parts of the multiplication formula 2×4=8?

(5) Teacher's summary: Find out a * * *, how many computers there are, that is, how many computers are four twos, which can be calculated not only by addition, but also by multiplication. It can be written as "2×4=8" or "4×2=8" and can be read as "2 times 4" and "4 times 2". The equal sign is preceded by a multiplier and followed by a product.

4. Teach "Give it a try"

(1) Let's give an example, and talk about the meaning first.

(2) Question: How many groups of chickens are there in the picture? How many chickens are there in each group? One * * *, how many, or how many altogether?

(3) Students write an addition and two multiplication formulas and communicate collectively.

(4) discussion; What's the sum of five fours? Which is simpler to write?

Say and calculate the formula.

Say it.

Say it first, then fill it in and complete the "try it".

Tell me the formula.

Read it.

Name the parts of the addition formula.

Students at the same table talk to each other about the names of the parts in the multiplication formula.

Say it.

Answer the questions before filling in.

Third, complete "Want to Do" 1 ~ 5

1, complete "think and do" 1

Show the picture of 1 and ask: How many sticks are there in the box of 1? How many boxes? A * * *, how many branches, that is, how many?

Students fill in the blanks independently.

2. Complete "Thinking and Action" 2

Students finish the second question independently, and exchange key questions in groups. How many flowers do you want?

Step 3 Complete "Thinking and Action" 3

(1) Put a pendulum with a disc, two in each pile, four in each pile, and call the roll. How much did you put in?

Students write an addition formula and two multiplication formulas independently and communicate collectively.

(2) Put a pendulum with a disc, 4 in each pile and 2 in each pile. Call the roll and answer: How many did you put?

Students independently write addition, subtraction, multiplication and division formulas and communicate collectively.

(3) What are the similarities and differences between these two arrangements?

4. Complete "Thinking and Action" 4

Read the multiplication formula and say what the multiplier and product are. Students at the same table talk to each other first, and then call the roll.

Step 5 Complete "Think and Act" 5

Complete independently and communicate collectively.

Complete "Want to Do" 1-5.

Fourth, summary.

What did we learn today?

Say it.

Matters needing attention after teaching: