1, oral multiplication

Lesson 65438

Teaching content: P 1 example 1, P2 example 2 oral multiplication.

Teaching requirements: master a method of multiplying a number by whole ten, whole hundred and whole thousand; And can perform oral calculation accurately and quickly.

Teaching methods: slides, sticks, dictation cards, etc. And operation.

Teaching process:

First, knowledge bedding:

1. multiplication formula in the table (can be done with a calculator card).

How many pieces is 2.50 10? How many hundred is 700?

3.8 How much is ten? 24 10? What about 2400?

4.5 What's two?

Second, the new teaching:

1. 1 example 1

(1) Instruct students to release sticks: for every two bundles (each bundle 10), put three piles.

(2) Inspire students to discuss: How many sticks can a * * * calculate?

Addition: 20+20+20=60

Calculated by multiplication: 20X3=60

(3) Guide students to look at the real thing and understand the thinking process of calculating 20X3: 3 twos are 6, 3 twos (2 tens) are 6 bundles (6 tens) and 6 bundles are 60, that is, 3 twenties are 60. The result is the same as addition.

2. Summary: Find the number of three twenties, which can be calculated by multiplication. Think of it as 20×3:

2 x 3 = 6 x 10 =60

3.P2 Case 2

(1) Show the slide of Example 2, and let the students master the quantitative relationship after observation. There are 300 small wooden blocks in each pile, and there are 4 piles in one pile.

(2) Let students directly use the multiplication formula to find out how many pieces there are in a * * *.

(3) Ask students to calculate the results orally and express their thoughts.

(4) Summary: Find the number of four 300 s and calculate with 300X4. Think like this:

3 white× 4 =12 white = 1200

Third, practice design:

1.p 1 "Do it" 2. P2 "Do it".

Fourth, homework:

1, review 1 case 1, P2 case 2. 2.P4 question 1 and 2.

second kind

Teaching content: P3 cases 3 and 4, one digit multiplied by two digits, and one digit multiplied by hundreds of dictation.

Teaching requirements: master the oral calculation method of multiplying one digit by two digits and hundreds digits (each product is less than ten), and be able to perform oral calculation correctly.

Teaching means: audio-visual teaching.

teaching process

First, knowledge bedding:

1.P3 Textbook Review Content.

How many hundred is 2.450? How much is ten yuan?

Second, the new teaching:

1, P3 Case 3

(1) Learn arithmetic by looking at pictures. Guide students to observe the meaning of pictures carefully;

There are three 10 on the left, which is 30.

There are three 2s on the right, which are 6.

Make the students understand that there are 1 tens and two ones in 12, and three 12 are the sum of three 10 and three twos.

(2) Graphology algorithm; Generally speaking, oral calculation starts from a high position.

Think of it this way: 10×3=30 2×3=6 30+6=36.

(3) Guide students to read P3 case 3 and ask questions. Ask the students to dictate the steps of 12X3.

(4) Summary: One digit multiplied by two digits can divide a factor into integer ten digits and one digit, then multiply it by another factor and add it.

2.P3 case 4

Let the students try to draw inferences from example 3. Then, through the discussion of four people, the method of derived calculation can be summarized; Then the representatives of each group report the discussion results to the whole class, and finally the teachers and students sum up together.

Summary: 120 consists of 1 100 and 20, and 120×3 is the sum of 303 twenties. Think like this when calculating: 100×3=300, 20× 3 = 60,300+60 = 360.

Third, practice.

1, P3 "does" in Example 3.

2.P3 "Do" in Example 4.

Question 1: After the calculation, make comments and let the students express their thoughts. Encourage students, who can think of other oral calculation methods? "Question 2: After the students are independent, please ask the junior students to perform purposefully; Correct mistakes in time. The third question can be carried out in the form of a train race.

3. There are 2 1 white table tennis, and the number of flower table tennis is twice that of white table tennis. How many flower ping-pong balls are there? How many ping-pong balls are there?

Homework: 1. Review P3 cases 3 and 4. 2.P4 Questions 4 and 5.

The third category

Teaching content: P4 Exercise 6- 1 1.

Teaching requirements: consolidate the calculation method of oral multiplication and skillfully use the oral calculation method: I am correct in oral calculation.

Teaching means: slide show

Teaching process:

First, knowledge bedding:

1. Multiplication formula in the table.

2. oral multiplication.

Second, practice design:

1. Fill in the blanks:

(1)2 1×3 can be read as () times (), and the product is ().

(2)3×6 is pronounced as () multiplied by (), which means that () is added.

(3)32× 3 is pronounced as () times (), which means how many times is ()?

2. Do questions 7, 8, 9, 10, 1 1 in the textbook.

When doing questions 7, 8 and 10, we should pay attention to the use of various forms, such as comparing who drives the train faster or in groups, and seeing which group arrives at the destination first to win the red flag and improve students' interest in learning.

Question 9 is an application problem with redundant conditions. How many times is a number? When practicing, we should decide whether to give students appropriate tips according to the actual situation of the students in this class, and pay special attention to counseling middle and lower students.

3. The questions12 and 13 are for students who have the spare capacity to finish independently, and they will be conducted in class or after class according to the actual arrangement.

4. think about the problem. You can make active slides to help students understand the meaning of the question. It is clear that no matter which way you take from Xiaohua's home to the park, there are four ways to get to the park after you get to school. Students can also draw, count and find patterns in the pictures in the book to achieve the same goal.

After each exercise, you should make a good evaluation and revision.

III. Homework: 1. Recite multiplication formula.

2.P4 question 6, P5 question 10.

2. Pen multiplication

One digit times two, three and four digits.

Lesson 65438

Teaching content: P6 case 1, case 2.

Teaching requirements: master the calculation method of multiplying one digit by two or three digits and the vertical writing format, be able to calculate correctly and cultivate the habit of careful inspection.

Teaching means: audio-visual teaching

Teaching process:

First, knowledge bedding:

The contents reviewed in P6 textbook. Oral multiplication and vertical writing format.

Second, the new teaching:

1.P6 case 1

① Introduction from oral calculation: After putting forward the topic, ask "What do you think when you use oral calculation?"

② Written calculation method: With the help of P6' s physical diagram, guide students to read out the calculation process step by step in the box surrounded by P6' s dotted line.

③ Summarize the calculation method.

2.p7 Example 2

(1) Let the students deduce the calculation method based on the example 1, and deepen their understanding of multiplying a single digit by multiple digits. The key point is to get 4% by multiples of 2% and write it on 1% of the product.

(2) Pay attention to the vertical book format.

(3) By guiding students to read the contents of "attention" in the textbook, let them do the multiplication operation of Example 2 again, and tell them that the multiplication operation can be checked again later, so as to cultivate the habit of careful inspection.

Third, practice design:

1. Textbook P6 "Do it".

2. Teaching material P7 "Do it".

3. Do P7, question 1, first run, question 2, first run.

Homework: 1. Review P6 case 1, case 2. 2.P7, question 1, horizontal.

second kind

Teaching content: Exercise 2, Questions 3-9

Teaching requirements: consolidate the calculation method of multiplying one digit by two or three digits and the vertical writing format.

Teaching means: slide show

Teaching process:

First, review.

Written calculation 2 13×2 24×2

Second, practical design.

1. Practice 1, question 3. Let the students read the questions first and then analyze the answers.

2. Exercise 1, question 4. Write down the following questions.

3. Exercise 1, question 5, column calculation.

4. Exercise 1, question 6, and calculate the following questions orally.

5. Exercise 1, questions 7 and 8, application questions.

6. Exercise 1, question 9, informal calculation.

Third, homework

Review page eight of the textbook.

The third category

Teaching content: textbook P9 case 3, P 10 case 4.

Teaching requirements: master the calculation method of multiplying one digit by two or three digits in discontinuous carry, and be able to calculate correctly and skillfully.

Teaching means: slide show, one stick for each student.

Teaching process:

First, knowledge bedding:

Textbook content P9 comments:

5×3+6 2×9+7 6×8+3 4×7+5

Second, the new teaching:

1, P9 case 3 24×3=

(1) swing.

① Put 2 bundles in the first row. (per bundle 10), and the other 4 pieces.

(2) Put two more lines as the first line.

(2) Guide students to observe and answer questions; List formulas;

(1) How many are there in each row? * * * A few lines?

(2) Three rows and one * * *, how many do you need?

(3) clear arithmetic in hands-on operation.

What's three plus four? What if it exceeds 10?

② How many bundles are three 2 bundles? Plus just a bundle, how many bundles is a * * *?

(3) How many bundles does A * * * have?

(4) Observe the slide pictures and learn the algorithm.

(5) Guide students to read P9 case 3 and ask questions.

(6) Let the students say how 72 is calculated.

2. Teaching of Example 4

(1) Read the questions and tell the order of multiplication.

(2) Guide students to complete the textbook P 10 Case 4.

Summary: Let the students talk about how to calculate P 10 case 4. Focus on how much the tenth digit of the first factor is multiplied by 9, how much 1 should go forward, and how the hundredth digit of the product gets 7.

Third, practice design.

1. Make textbooks P9 and Pl0.

2. Textbook P 1 1 Question 2.

3. calculation;

42×3 15×2 27 1×3 5 16×4

4. Calculate the relay race. (Divided into four groups, 3 people in each group)

(Except for the participating students, the judges will mobilize the enthusiasm of all students.)

Fourth, homework; '

1. Review P9 case 3 and P 10 case 4.

2. Question 1 1.

Category 4

Teaching content: Exercise 3, Questions 3-9

Teaching requirements: master the calculation method of multiplying one digit by two or three digits in discontinuous carry, and be able to calculate correctly and skillfully.

Teaching means: competition

Teaching process:

First, review.

A multiplication rule in which one factor is a single digit.

Second, practice design:

1. The third question of calculating P 1 1

3.P 1 1 Question 6 was revised by students independently.

4.P 1 1 questions 4 and 5.

5.P 12 question 7 is the form of the competition to see who gets all the answers correctly in the shortest time.

6.P 12 questions 8 and 9 can be used as the content of the activity class because of time. Question 10 reminds students to find out the rules before filling in the form.

Fourth, homework:

Review the content of P9 1 1, and understand and remember the multiplication rule of one digit.

The fifth category

Teaching content: P 13 case 5.

Teaching requirements: master the method of continuous carry in one-digit multiplication and calculate it correctly.

Teaching means: audio-visual teaching

Teaching process:

First, knowledge bedding:

1. Textbook P 13 Review contents.

2. Modify after calculating 5 17×3, and let the students talk about what should be paid attention to when calculating.

Second, the new curriculum teaching.

1.p 13 teaching case 5.

(1) Show the diagram of Example 5 with slides and ask students to list the multiplication formula: 454×4.

(2) First, students try, modify and learn through collective comments.

(3) Compare Example 5 with "knowledge bedding" (2) in this section to find out the similarities and differences, so that students can understand the truth of carry.

2. Summary: "When a factor is a one-digit multiplication calculation, it should be noted that when one digit of the first factor is multiplied by one digit, it depends on whether the product multiplied by the last digit has a carry. If there is a carry, don't forget to add it. "

Third, practice design:

1.P 13 "Do it"

After the revision, ask the students to find out which question is most likely to make mistakes and why.

2. Fill in the appropriate numbers:

4. Introduction P 14 "Do you know? Broaden students' horizons and cultivate their interest in learning.

Fourth, homework:

1. Review P 13 Case 5. 2.P 14 problem 1 and 2.