The first part: the teaching objectives of the fourth grade mathematics teaching plan (selected) in primary school mathematics;
1. Understand verticality with the help of actual situation and operation activities.
You can draw a vertical line with a triangular ruler.
3. It can solve some simple problems in life according to the principle that the vertical line segment between points and lines is the shortest.
4. Cultivate students' spatial concept and preliminary drawing ability.
Teaching focus:
Establish the concepts of intersection and verticality, and draw vertical lines with a triangular ruler.
Draw a vertical line and solve the problem according to the principle that the vertical line segment between points and lines is the shortest.
Teaching difficulties:
In order to establish the concepts of intersection and verticality, vertical lines will be drawn with a triangular ruler.
Teaching process:
First, create situations and learn new knowledge.
1. Wave a stick.
Please take out two sticks and form two parallel straight lines.
2. Think about it.
What can two straight lines do besides being parallel? Crossroads.
3. Write on the blackboard.
Parallel intersection.
Second, learn new knowledge.
1. Let's have a look.
Put all kinds of intersecting figures on the table with a small stick.
Observe, what do you find in so many intersecting figures?
Summary: When two lines intersect at right angles, they are perpendicular to each other.
2. Compare perpendicularity and intersection.
Discuss at the same table: What are the similarities and differences between verticality and intersection?
Ask the students to erect vertical numbers.
And tell me how you can tell whether they are perpendicular to each other.
3.give me a discount.
Take out a rectangular piece of paper and let the students think. By folding it, can you fold lines perpendicular to each other?
Ask the students to try a discount. If there is any difficulty, they can finish each other at the same table.
Put forward the activity request: take out a square and fold it in half so that the two creases are perpendicular to each other. After folding, ask the students to draw each group of broken lines in different colors, which is easy to distinguish.
Show the students' works and let them tell how you verified that they were vertical.
4. find it.
There are many vertical lines in our life. Can you talk about the vertical line in our life?
5. I said you put it there.
Complete the question 1 on page 22 of the book.
Applications in life: take a look. What did you find?
6. Learn to draw vertical lines.
Question: Can you draw two vertical lines?
Learn to try to draw a vertical line by yourself.
Show, report and communicate: Why do you draw like this? Tell me the reason for this painting?
Summary: Draw a straight line with a ruler, mark a point, and draw a vertical line through this point.
Specific steps: overlap a right-angle side of the triangular ruler with this straight line, the vertex of the right angle is the vertical foot, and draw a straight line along this right-angle side, which is the vertical line of the previous straight line.
The teacher said and demonstrated.
Deskmate operation: Draw a line perpendicular to each other at a point outside the straight line. Feedback communication.
Third, consolidate practice.
The little experiment on page 23 of the book.
Question: What's the shortest way to the river?
Discuss in groups.
The whole class reports and exchanges.
Teacher's question: How many possibilities are there from point O to straight line AB?
Contrast: What do you find in so many line segments? Which one do you think is the latest? Why?
Four. abstract
A point outside the straight line leads to the shortest vertical line.
Blackboard design:
Intersection and verticality
Specific steps: overlap a right angle edge of the triangular ruler with this straight line, and the vertex of the right angle is the vertical foot, along the
This right angle draws a straight line, which is perpendicular to the previous straight line.
Chapter two: The fourth grade mathematics teaching plan (selected) the content of primary school mathematics teaching.
Textbook page 1 10, question 2, "Exercise 2 1", questions 4-8.
Teaching objectives
1. Make students further master the oral and written calculation methods of multiplying three digits by two digits and dividing by two digits, and improve their calculation ability.
2. Use calculation to solve practical problems in daily life and improve the ability to solve problems.
Important and difficult
Key point: clever calculation.
Difficulties: solving practical problems.
teaching process
First, review and organize.
1. orally calculate the following questions.
23×4= 230×4= 18×3= 7×50=
54÷3= 540÷3= 60÷30= 250÷50=
The teacher shows the cards and the students practice oral arithmetic.
Choose a question by multiplication and division, and let the students talk about the method of oral calculation.
2. Show the second question on page 1 10 of the textbook.
(1) Discussion: What should I pay attention to when writing multiplication and division?
Organize students to discuss and exchange in groups, and then call the roll.
① Pay attention to counterpoint and carry when calculating multiplication.
② Pay attention to the trial quotient when calculating division, and the remainder must be less than the divisor.
(2) Analyze the causes of these errors.
Group discussion and conversation.
(3) Correct these problems in your exercise book.
3. Write the product or quotient of the following two questions directly without calculation.
15×39=585 792÷24=33
150×39= 396÷ 12=
15×390= 1584÷48=
4. Tell me about the basis of calculation: What is the changing law of product sum quotient?
5. Solve practical problems.
Show the sixth question in the textbook Exercise 2 1 by projection.
(1) Read the questions by name and understand the meaning.
(2) Group discussion: What is the quantitative relationship among unit price, quantity and total price? Given the total price and unit price, how to find the quantity? Talk about the problems in the problem separately and then calculate.
(3) What are the common quantitative relationships in life?
Let the students discuss and say.
Second, practical application.
Problems 4, 5, 7 and 8 in the textbook Exercise 2 1.
1. Question 4.
(1) Organize students to practice.
(2) Intra-group communication inspection.
2. question 5.
(1) Students practice independently.
(2) Talk about inspection methods.
3. question 7.
(1) Do not count direct writes.
(2) Tell me what you think.
4. question 8.
(1) Students do it independently.
(2) report the answering process by roll call.
300 \4 = 75 (yuan) 75× 12=900 (yuan)
Third, the class summary
In the process of calculation, it should be calculated carefully according to the requirements of the topic, and can also be checked by estimation after calculation.
Chapter 3: The teaching content of the fourth grade mathematics teaching plan (selected)
Page 7 1 of the textbook is an example of 1 and 2.
Teaching objectives
Master the oral calculation skills of division with divisor as two digits, can correctly perform oral calculation and estimation, and cultivate calculation ability.
Important and difficult
Key points: master the oral calculation method of dividing by two digits.
Difficulties: Understanding divisor is an estimation method of two digits.
teaching process
First, create a situation
1.
20×3= 60÷3= 30×9= 270÷3=
39÷4≈ 84÷6= 3 1÷3≈ 72÷4=
26÷5≈ 54÷3= 43÷6≈ 75÷5=
The teacher used cards to show the oral math problems and named them respectively.
2. How to divide by mouth when the divisor is two digits?
(Title on the blackboard: Formula)
Second, independent inquiry.
1. Teaching examples 1.
Projection example 1: There are 80 colorful flags, and each class is divided into 20. Can be divided into several grades?
(1) Find out the meaning of the problem and analyze the conditions and problems. You can be divided into several classes, that is, how many twenties are there in 80.
(2) Exponential formula: 80÷20= (blackboard writing)
(3) Can you work out this problem with your mouth? what do you think?
Students may have the following algorithms:
A.8 ÷ 2 = 4 B. () 20 equals 80…
80÷20=4 80÷20=()
The teacher finished answering.
2. Think about it: 83 ÷ 20 ≈ 8019 ≈.
(1) Organize students to discuss in groups, talk about their own ideas, and then report by name.
(2) What is the relationship between the above two formulas?
(Both can be calculated by 80÷20)
3. The textbook page 765438 +0 "doing" question 1.
Pay attention to the differences between each set of formulas. Let the students finish the exam independently, and then communicate the exam in the group.
4. Teaching example 2.
Let the students read the questions by themselves, complete them independently, answer them in the textbook and tell how you worked them out.
5. Complete the second question of "Doing" on page 7 1 of the textbook.
Students practice and the whole class corrects collectively.
Third, practical application.
1. Textbook exercise 12 The first 1 question.
Students practice independently and review collectively.
2. The second question in the textbook Exercise 12.
Name the solution and see who can work it out correctly and quickly.
3. Questions 3 and 5 in the textbook "Exercise 13".
Ask to read the meaning of the question first, and then answer it in columns.
What do you mean by "limited to 40 people"? This means that you can only carry 40 passengers at a time.
Students practice independently and review collectively.
4. Questions 4 and 6 in the textbook Exercise 12.
Three students perform on the blackboard, the rest practice, and then correct collectively.
5. Question 7 in the textbook Exercise 12.
Students practice independently and review collectively.
Fourth, class summary.
Let's talk about the connection and difference between divisor and two-digit oral estimation.
Chapter four: the teaching objectives of the fourth grade mathematics teaching plan (selected);
1, in the actual situation, let students know the commonly used land area unit hectare, experience the actual size of 1 hectare and 1 square kilometer through actual observation and calculation, and establish the appearance of 1 hectare and 1 square kilometer; Knowing 1 hectare = 10000 square meters, we can simply convert units.
2. Let students use the knowledge of area formula and area unit conversion of plane graphics to solve some simple practical problems.
3. Make students experience the exploration of mathematical problems in learning activities, feel the connection between mathematics and life, and cultivate students' ability to cooperate with each other.
Teaching focus:
1, understand the meaning of hectares and square decimeters. Master the conversion relationship between area units.
2. Experience the actual area 1 hectare, 1 square decimeter.
Teaching process:
I. Organizing teaching
Review the areas of rectangles and squares.
Second, show the teaching objectives
It is the teacher and students who read the goals together and establish the focus of this class.
Third, the teacher's excellent lecture.
(A) create a situation to reveal the topic
Last class, we knew that Xiaoming had moved to a new home. Today, Xiaoming happily invited the children to visit his new home. Click on the courseware: Show the situation map.
2. Look, where are they now?
3. Observe the picture. What did you find? What questions do you want to ask?
With so many questions, let's walk into the world of hectares together.
(2) Know the hectares and feel the size
(1), physical education class 100 meters, everyone ran away? Can you imagine how long 100 meter is?
If four runways 100m form a square, can you calculate the area of the square? (3) Summary: Mathematically, we define the area of a square with a side length of 100 m as 1 hectare. Through calculation, we know that the area of such a square is 10000 square meters, so we can know: 1 hectare = 10000 square meters.
So, can you appreciate the area of 1 hectare?
Before class, we asked 28 students to form a square hand in hand, so the area of the enclosed square is about 100 square meter.
Everyone surrounded a square like the one in the photo. /kloc-Can you appreciate the area of 0/00 square meter?
(3) 10000 square meters how many such squares do you need to spell?
100 The square area is about 10000 square meters, which is 1 hectare. Can you imagine the scale of 1 hectare now?
3. Feel the life 1 hectare.
If you still can't understand the size of 1 hectare, let's go into life, find 1 hectare, and then understand the size of 1 hectare.
Q: Do you see where this is? 4. Know the square kilometers
(1) We know how big 1 hectare is. Is there an area unit larger than hectares?
⑵ Summary: The area of a square with a side length of 1000m is 1km2, which can be written as 1km2.
1 km2 = 100 hectare
Third, go into life and solve problems.
Lead: Unconsciously, everyone has solved all the problems, not only knowing the area of 1 hectare, but also knowing the square kilometers. Let's use this knowledge together to help Xiao Ming solve some practical problems.
Xiaoming's mother gave Xiaoming these questions. Can you help him fill it out?
2 hectares = () square meters 50000 square meters = () hectares 3 square kilometers = () hectares 90000 hectares = () square kilometers.
Fourth, show the title
Fifth, expand and consolidate the application after class.
What did you learn from this class today?
Summary: We know several units of area-hectares and square kilometers.
Six, homework arrangement
After class, please investigate the area where you live and the area of Weiqiao Town.
Chapter five: the teaching objectives of the fourth grade mathematics teaching plan (selected);
1. Let students know the common unit of land area-hectare, how big it is, and the relationship between 1 hectare and square meters.
2. Cultivate students' spatial concept and practical ability.
Teaching focus:
What is the spatial concept of 1 hectare?
Teaching difficulties:
Conversion between square meters and hectares.
Teaching aid preparation:
Datum and rope.
Teaching process:
First, review the preparation.
1. What is the area? What are the commonly used area units? The size of an object's surface or plane figure is called its area. Common units of area are square meters, square decimeters and square centimeters.
2. What is1m2? What is 1 square decimeter? What is 1 cm2? (A square with a side length of 1 m and an area of 1 m2; A square with a side length of 1 decimeter and an area of 1 square decimeter; A square with a side length of 1 cm has an area of 1 cm 2. )
3. 1 m2 = () square decimeter
3 square meters 5 square decimeter = () square decimeter
1 square decimeter = () square centimeter
1500 square centimeter = () square decimeter
Second, learn new lessons.
1. Session Introduction
Calculating the area of general objects includes square meters, square decimeters and square centimeters. Today we are going to learn the unit of calculating land area-hectare.
2. Understanding of hectares.
(1) The teacher said: Calculate the area of land in square meters and hectares. How big is 1 square meter? Everyone knows that a square with a side length of 1 m has an area of 1 m2. So how big is 1 hectare? Let's actually measure it.
(2) measured.
Lead the students to the playground. First, measure the square land with a side length of 1 m and enclose it with columns and ropes, indicating that such a large land is 1 m2.
Then measure the square land with a side length of 10 meter, surround it with columns and ropes, and ask the students how many square meters is this land? Let the students visit this land. 100 square meter. Then the teacher explained that 100 piece of land of this size 100 square meter is 1 hectare. Close your eyes and think about how big 1 hectare is.
(3) The relationship between hectares and square meters.
Back to the classroom, the teacher asks questions to stimulate students' imagination.
How big was the first enclosed square on the playground just now? What are their side lengths?
② What is the side length of the second closed square? How big is the area? (Teacher writes on the blackboard: 100m2)
(3)1hectare How many square meters of land is there? ( 100)
④ How many square meters are there in1hectare? How did you find out? ( 100× 100= 10000)
Teacher's blackboard: 1 hectare = 10000 square meters.
Teacher's Note: The classroom area is generally 50 square meters, and the area of 200 classrooms is about 1 hectare.
1 hectare = 10000 square meters, so how many square meters is 2 hectares?
30,000 square meters = () hectares.
(4) practice.
4 hectares = () square meters 50000 square meters = () hectares
3. Teaching examples.
(1) Teacher's Note: When measuring land, meters are generally used as the unit of length, and the area is converted into hectares after calculation.
(2) For example, a rectangular orchard is 250m long and120m wide. How many hectares is this orchard?
Ask a question
① How to find the rectangular area?
② How to convert square meters into hectares?
Continuous calculation by students.
(3) practice.
How many hectares are there in a square wheat field with a side length of 400 meters?
All the students do it in the textbook, and one student does it on the slide. Ask the students what they think when revising. Given the side length of a square, what can you find? How to convert it into hectares?
Third, consolidate feedback.
1. Practice in class.
(1) Tiananmen Square in Beijing is the World Square, with an area of about 40 hectares, or about () square meters.
(2) The Forbidden City in Beijing is a palace in the world, covering an area of 720,000 square meters, or () hectares.
2. Practice after class.
(1) Measure the length and width of the school playground and calculate its area to see if it is 1 hectare.
(2)7 hectares = () square meters 60000 square meters = () hectares
(3) An airport will build a new runway with a length of 250m and a width of 80m. How many hectares does it cover?
Blackboard design:
Land area unit-hectare
For example, a rectangular orchard is 250 meters long and 120 meters wide. How many hectares is this orchard?
250× 120=30000 (m2)
30000 square meters =3 hectares
This orchard covers an area of 3 hectares.
Land area unit: square meters, hectares.
1 ha = 1 10,000 m2