1, through the observation, abstraction and generalization of the theme map, let students realize that calculation comes from solving problems, and calculation comes with solving problems.

2. On the basis of students' extensive questions, introduce 7? The multiplication formula of 9 is used to find the quotient.

3. Cultivate students' independent exploration, cooperative communication, language expression ability and analytical judgment ability. 4. Find the quotient by multiplication formula of 7, 8 and 9, and solve simple practical problems by division calculation.

5. Cultivate students' comprehensive mathematics ability and stimulate patriotic enthusiasm.

Emphasis and difficulty in teaching

Teaching focus:

Learn to use the multiplication formula of 7, 8 and 9 to find the quotient.

Teaching difficulties:

Further master the problem-solving methods of basic application problems of division and develop students' problem-solving ability.

teaching tool

courseware

teaching process

First, review the old knowledge.

Teacher: Before class, the teacher wants to test you. Are you confident to pass? Please look at the first question (computer demonstration) (in the form of driving a train)

1. Complete the following formula.

Eight 56, three 27, six 54.

Seven () 632 () 18 () 728.

2. Calculate the following questions.

24? 6 15? 3 24? 4 9? 3 8? four

Choose one or two names, talk about how you seek business, and give the students who speak well a rabbit head as a reward. )

Design intention: review the related formulas of multiplication, pave the way for learning the quotient of division, and review the operation of finding the quotient with the multiplication formula of 2 ~ 6, so as to arouse students' memory of the existing knowledge.

Teacher: Students, you can use the multiplication formula of 2-6 to find the quotient. In this lesson, we will learn how to compare quotients with multiplication formulas of 7, 8 and 9 to see who can learn quickly.

Blackboard Writing: Finding Quotient by Multiplication Formula of 7, 8 and 9

Second, scenario introduction and cooperative exploration:

Teacher: The students behaved so well that the teacher decided to take you to bright primary school. Do you want to go? They celebrate Children's Day on June 1. Decorate your classroom beautifully. Look, what are they doing (the courseware shows P48 scene diagram).

1, discover mathematical information

Health: Some are making colorful flags, some are making five-pointed stars, and some are preparing colorful balloons.

Teacher: The students watched carefully. What mathematical information can you find from the picture? Health: I made 56 colorful flags and hung 8 rows. Made 49 five-pointed stars and distributed them to seven friends. Bring 27 colored balloons in a row of nine. Show three groups of information in the order of students' answers.

Step 2 ask math questions

Teacher: Can you ask math questions based on this information? Please think about it, and then share your problems at the same table.

Student: The group has made 56 colorful flags, which will be hung in 8 rows. How many flags should be hung in each row on average?

Student: The group made 49 five-pointed stars and distributed them to seven friends. How many five-pointed stars did each partner get?

Student: The group brought 27 colored balloons, with a row of 9 balloons. How many rows can I put?

According to the order of students' answers, show three targeted math questions in turn.

Step 3 solve math problems

Can you solve these problems? Please choose a problem in groups and solve it with what you have learned. A capable team can solve these three problems.

4. Exchange solutions to problems

Which group of children are willing to share your solution to the problem with you?

Solve? I made 56 colorful flags. How many flags should I hang in 8 rows?

Teacher: What is the formula? how much is it? Health: 56? How to calculate 8=7 (face)?

Health: Because seven, eight, five and sixteen, so 56? 8=7。 Why use the formula 7856 to seek business, instead of using other formulas? Because the divisor is a few, I thought of the multiplication formula of several.

Teacher: Great! Are other students in the same group? Do you have any different opinions? Teacher, here's another question. Would you like to help me solve this problem? All right! What if you hang seven rows? Answer by name and answer by life. How to do business? The teacher drew the conclusion that how many faces need to be hung in each row can be calculated by division, 56? 7=8 (face), so it is 56? 8=7.

5. Observation formula

Teacher: What did you find from the research just now?

The teacher led us to the conclusion that one multiplication formula can calculate two division formulas. The teacher gives questions at random and then evaluates them.

6. Teaching the second question

The students are very clever. They answered the teacher's questions. It's amazing! So now let's solve the second problem. Computer demonstration: point out the answers and focus on how students ask for business. Just now we said that one formula can calculate two division formulas. Do you think this formula is ok? Why? What other formulas are there like this?

7. Solve the third problem.

You guys are amazing! Who will solve the third problem? Point out the answer and then immediately point out how to hang up the phone. Well, we also use the same formula for these two formulas.

8. Summarize the solution to the problem.

Teacher: 49? 7、27? Just now we calculated these formulas (56? 8、56? 79), which multiplication formula are used respectively?

Health: Use the multiplication formula of 7, 8 and 9.

Teacher: So today, we are going to learn to find the quotient by using the multiplication formula of 7, 8 and 9. Random blackboard writing

Teacher: Just now, you were all very clever. The children in bright primary school really want to make friends with you, so they invite you to spend the holidays with them. Do you want to go? Look! The train is coming! But my aunt said you had to pass her challenge to get on the bus. Are you confident to pass? All right!

Third, consolidate and improve.

1, 1 level: Blow bubbles (there is a question on each bubble, and you got it right. This bubble wine belongs to you. Who wants to take the first bubble? )

2. Level 2: Do and tell me your findings?

3. Level 3: Rabbits cross the river (let students discuss how to get to mushrooms first)

4. Level 4: Birds go home.

5. Level 5: See who is the best.

Teacher: The train is leaving! You are doing very well. I'm proud of you. Let's congratulate us with applause!

Four. abstract

Teacher: What did you learn from this class?

Write on the blackboard.

Find the quotient with the multiplication formula of 7, 8 and 9.

56? 8=7 56? 7=8

Think: Formula 7856 Think: Formula 7856

49? 7=7 36? 9=4

Think: Formula 7749 Think: Formula 4936.

Teaching plan "Seeking Quotient by Multiplication Formula of 7, 8 and 9" (2) Teaching objectives.

Knowledge and skills

Let the students go through the process of finding the quotient by multiplication formula 7, 8 and 9, master the general method of finding the quotient by multiplication formula, and form the calculation skills of finding the quotient by multiplication formula.

Process and method

Let students experience the formation process of the calculation method of quotient of multiplication formulas of 7, 8 and 9, and experience the ideas and methods of migration, analogy, induction and generalization.

Emotional attitudes and values

Cultivate students' cooperative consciousness, improve students' exploration ability and feel the application value of mathematics.

Emphasis and difficulty in teaching

Key points: master the multiplication formula of 7, 8 and 9 to find the quotient.

Difficulties: Understanding the operation of the multiplication formula of quotient.

teaching tool

multimedia courseware

teaching process

(A) the introduction of new courses

The courseware shows the theme map on page 37. )

Children's Day is coming, and the children are busy decorating their classrooms under the guidance of their teachers.

1. Guide observation and collect information

Question: What did the child in the picture prepare? What mathematical information did you get through observation? (Answer by name)

(1) The students in the first group made some small flags to hang in the classroom.

(2) The students in the second group made 49 stars, which should be divided into seven groups.

(3) The students in the third group brought 27 colored balloons, and every nine balloons should be arranged in a row.

2. Organize information and ask questions.

According to this mathematical information, what mathematical questions can you ask?

Let the students think about it first, then talk to each other at the same table and report by name.

Teachers according to the student report summary:

(1) How many sides does each line hang on average?

(2) How many capsules are there for each ingredient?

(3) How many lines can you put?

(2) Explore new knowledge

Example on page 38 of the textbook 1.

Example 1 taken from the theme map: There are 56 flags hanging in 8 rows. How many flags are hung in each row on average? How can I work it out?

(1) Instruct students to list the formulas by division: 56? 8= (teacher writes on the blackboard)

Q: Can you try to do it yourself?

Students try to calculate independently and exchange ideas in groups.

(2) report by name. Encourage students to say it in different ways. )

(3) Q: Which method is the simplest? (Find the quotient by multiplication formula)

Guide the students to sum up: beg for 5? 8 quotient, think of seven times eight to get 56, then 56? The quotient of eight is seven.

(4) Change the conditions in the above question: What if it is hung in 7 lines?

Can you find 56 with the multiplication formula? Is the quotient of this formula.

(5) Communication: Tell me how you worked it out.

Let the students form independently and the teacher patrol.

(The teacher writes on the blackboard: 5? 7=8)

2. Example 2 on page 39 of the textbook.

Example 2 is taken from the theme map.

(1) The teacher looked at the question and asked: How to solve it continuously?

The teacher answers the blackboard according to the students: 27? 9=

Organize students to cooperate in groups and exchange ideas in groups.

(2) The group reports in turn.

Guide the students to sum up: beg 27? The quotient of 9 thinks that 3 times 9 gets 27, so 27? The quotient of nine is three.

(3) Change the questions and do oral calculations independently.

Can you find 27 with the multiplication formula? Is the quotient of this formula.

(4) Communication: Tell me how you worked it out.

Let the students form independently and the teacher patrol.

(3) Consolidate exercises

1.7? 4= 8? 2= 8? 6=

28? 4= 16? 2= 48? 6=

28? 7= 16? 8= 48? 8=

Attached answers: 28, 7, 4; 16,8,2; 48,8,6

2.5? ( )=35 6? ( )=42 49? 7=( )

32? 8=( ) 24? 8=( ) 8? 8=( )

Attached answers: 7, 7, 7, 4, 3, 64

3. Eight five six seven six three

Three () 276 () 54

Eight, seventy-two and seventy-eight.

() 848 () 742

Attached answers: seven, nine, nine, nine, nine, four, six, six.

(4) expansion and upgrading

1、7? 9= 8? 9= 9? 6=

63? 7= 72? 8= 54? 6=

63? 9= 72? 9= 54? 9=

Attached answers: 63, 9, 7; 72,9,8; 54,9,6

Attached answer: 36? 4,8 1? 9,27? 3,45? 9,54? The quotient of 6 is 9.

2 1? 3,35? 5,42? 6, 14? 2,28? The quotient of 4 is 7.

16? 2,64? 8,32? 4,48? 6,56? The quotient of 7 is 8.

2、

27? 9= 48? 8= 24? 8=

36? 9= 35? 7= 14? 7=

42? 7= 18? 9= 72? 9=

56? 8= 64? 8= 2 1? 7=

Attached answers: 3, 6, 3, 4, 5, 2, 6, 2, 8, 7, 8, 3.

Summary after class

What skills have you learned through the inquiry activities in this class?

1, learned to use the multiplication formula of 7, 8 and 9 to find the quotient.

2. Master the method of seeking quotient by multiplication formula.

I understand the importance of cooperation with peers and the value of mathematics in daily life.

Write on the blackboard.

Find the quotient with the multiplication formula of 7, 8 and 9.

7? 8=56 Formula: 7856

56? 8=7 Thinking: (7) 856

56? 7=8 Thinking: 7 (8) 56

3? 9=27 Formula: 3927

27? 3=9 Thinking: (3) 927

27? 9=3 Thinking: 3 (9) 27