Teaching plan and teaching reflection of "knowing decimals" in third grade mathematics

# 3 # Introduction Decimals are special expressions of real numbers. All fractions can be expressed as decimals, and the points in decimals are called decimal points, which are the dividing lines between the integer part and the decimal part of a decimal. Decimals with zero integer parts are called pure decimals, and decimals with non-zero integer parts are called decimals. The following is the arrangement of the teaching plan of "knowing decimals" in the third grade of primary school mathematics and the related materials of teaching reflection, hoping to help you.

Teaching plan of "understanding decimals" in mathematics of grade three in a primary school

Teaching objective: 1. Understand decimals in combination with specific situations and understand their life background.

2. Know the practical significance of decimals in meters and yuan. Know that a few tenths of a score can be expressed in a decimal place.

3. Know the names of decimal parts, read and write decimals, and correctly distinguish between integers and decimals.

4. Infiltrate the connection between knowledge and stimulate students' interest in learning mathematics in life.

Teaching emphasis: understand the practical meaning of decimals in meters and yuan, and be able to read and write decimals.

Teaching difficulties: establish the relationship between one-tenth of the score and decimal, and experience the decimal value of decimal.

Preparation of teaching AIDS: courseware and study list

Teaching process:

First, life perception, introducing decimals.

1, confide: Students, math classes often deal with numbers, let's walk into the "kingdom of mathematics" together. The teacher brought you some commodity information. Please classify the main points on these price tags. How to divide it? (deskmate communication)

24 yuan weighs 3.45kg.

1 19 yuan 0.85 yuan.

10 yuan 2.60 yuan

Class communication: (tell the main points of sharing life)

The teacher asked: Why do you divide it like this? What's the difference between them?

The three numbers on the left have no dots, and the three numbers on the right have dots.

2. Introduction: The number on the left is the integer we have learned, and the number with dots on the right is called decimal. Decimalization is another new member of the digital kingdom. Today we will "know decimals" together. (blackboard writing topic)

What do you know about decimals?

4.which one are you familiar with? Can you talk about it?

Second, practice independently and know decimals.

1, the name of the decimal part.

Taking 3.45 as an example, the names of all parts of blackboard writing.

Teacher: The point in the middle of the decimal point is called the decimal point. (blackboard writing: decimal point) The decimal point is an important symbol of the decimal point. The decimal point divides the decimal point into two parts. To the left of the decimal point is the integer part; To the right of the decimal point is the decimal part. (blackboard writing)

2. Read decimals.

Who remembers how to pronounce this decimal? (3.45)

Teacher: It seems that you are listening carefully.

Students read 1, students read 2, and the whole class reads.

Teacher: Let's write down the pronunciation of this decimal. How many words did we read just now? After reading a few words, we wrote a few words. (blackboard writing)

There are many decimals in life. Let's read it together.

Teacher: Let your classmates read it. If you read it correctly, we will follow it. Raise your hand to correct it if you read it wrong.

Teacher: 36.36 Please read this decimal again. While reading it, think: When reading the decimal, do you read the decimal part and the integer part the same? How do you read it? Talk at the same table and report.

Student: Read the decimal part, and the "ten" in the middle will be removed.

Teacher: That is to say, when you read the decimal part, do you read it in whole numbers?

Health: No.

Teacher's summary: read the integer part by integer method, read the decimal part several times, just like reporting the telephone number, one by one, and then read it down in turn.

Understand decimals, let's walk into decimals together!

Third, understand decimals according to the situation.

(1) Understand decimals with the help of length units.

1, mark the corresponding length.

Show me the meter ruler: What mathematical information do you find by observing this line graph?

Student: A one-meter-long line segment is divided into 10 parts. Teacher: Mathematics should be rigorous and accurate, emphasizing "average"

Question: Divide 1 meter into 10. How many decimetres is each part? Why?

Health: 1 m = 10 decimeter. Divide 10 decimeter into ten parts, each part is 1 decimeter.

Read it all at once: divide 1 meter into 10 parts, each part is 1 decimeter.

Teacher: Knowing that each copy is 1 decimeter (blackboard writing), who can quickly tell us how long it is from the starting point to the place pointed by the arrow?

Mark 3 decimetres, 5 decimetres and 8 decimetres respectively.

Answer: 3 decimetres, 5 decimetres, 8 decimetres.

Teacher: Why is it 3 meters here?

Health: Because there are three 1 decimeter.

2, expressed in fractions.

1 decimeter? Why?

Default students: divide the line segment of 1 m into 10, and each part is110.

Teacher: 1 decimeter is 110, or110.

Teacher: What did the teacher say just now? Who knows? (blackboard writing110m)

How many decimetres can 3 decimetres, 5 decimetres and 8 decimetres be written? Please indicate these lengths in fractions on your homework paper.

Teacher: Why can 3 meters be written as 3/ 10 meters?

Default students: divide 1 m into 10, and take three of them, which is 3/ 10 m.

3. Decimal representation.

1 decimeter can be written as a fraction of110 meter or as a decimal of 0. 1 meter.

Teacher: Why write "0" in the integer part?

Default classmate: Because 1 decimeter is not enough, write 0 in the integer part.

Teacher: What does 1 mean?

Health: 1 means 1 decimeter.

Teacher: What does 1 mean?

Default student: 1 in 10.

Please use decimals to indicate other lengths on the worksheet.

Teacher: 3/10,5/10,8/10, what decimal number can you write?

Health: 0.3, 0.5 and 0.8.

Teacher: What do you think?

Health: 3 decimeters is not enough 1 meter, so the integer part should be written as 0 and the decimal part should be written as 3 in 10.

To sum it up. Question: Why are the integer parts of these decimals all 0? Look at these fractions and decimals. What did you find? (Vertical observation) What kind of fraction can be written as what kind of decimal? (A few tenths of a meter can be written as a few tenths of a meter; A few tenths of a meter can be written as a few tenths of a meter)

Teacher: What is the decimal between 0.3 and 0.5? What about after 0.8? What about after 0.9?

4. Exchange and discussion: 1.3 meters is written as () meters.

Health: written as1.3m.

Teacher: Why not write "0" in the integer part at this time?

Teacher: What does 1 in 1.3m mean? What does 3 mean?

(2) Further understand decimals with the help of elements, angles and minutes.

Show the courseware and make pictures:

1. Show me the map of RMB: Can you understand the meaning of this map?

Default students: 1 0.10 = 1 yuan,1yuan =10.10.

2. Student communication:

The angle of 1 is 1 yuan ().

Student: Because there is 1 01angle in1yuan, take one of them, that is110 yuan, or it can be written as (0. 1) yuan;

Teacher: Why do you write "0" in the integer part? What does "1" mean?

Health: "1" means 1 angle; One tenth.

Can you fill in the blanks independently on the homework paper like a teacher?

5 jiao is ()/() yuan, which can also be written as () yuan;

8 Angle is ()/() yuan, can also be written as () yuan;

8 yuan's 5 cents written as a decimal is () yuan.

Question: Why is 50 cents five tenths of a yuan? Why should I write 0 in the integer part of 0.5 yuan? therefore ...

Why don't you write 0 in the integer part of 8.5 yuan?

Fourth, consolidate exercises and expand decimals.

1, tens of meters can be expressed in decimals, tens of dollars can also be expressed in decimals, and the colored parts in the picture can be written in decimals. How to express it in decimal? Instant writing

Teaching plan of "knowing decimals" in mathematics of grade two and grade three.

Teaching objective: 1. Understand the meaning of decimals in combination with real life.

2. Can correctly identify, read and write decimals with no more than two decimal places.

3. Make students realize the close relationship between mathematics and life.

Mathematics literacy goal: to cultivate students' sense of numbers.

Teaching focuses on understanding the meaning of decimals and knowing decimals.

Significance of decimals in teaching difficulties.

teaching process

First, scene import

A preliminary understanding of decimals in life

Teacher: Look at the numbers in these pictures. Do you know them?

Student: Yes, it's a decimal.

What do you know about decimals?

Health: There are more points than integers.

Teacher: Numbers like 3.45, 0.85, 2.60, 36.6 are called decimals, and the middle points are called decimal points. This decimal point is a point and should be written in the lower right corner of the previous number.

Teacher: Can you choose a decimal that interests you and tell its meaning?

Health: 0.85 yuan is 85 points. 2.60 yuan means 60 cents in 2 yuan.

Teacher: What else can you tell me? It seems that everyone knows more about decimals representing prices, so let's know decimals from the prices we are most familiar with!

Second, explore new knowledge.

Decimal reading

Teacher: These are the price information collected by the teacher. Can you read these decimals? Who will try to read these decimals?

Health: Two and a half dollars.

Health: Two and a half dollars.

Health: One point zero five.

Health: One point zero five.

Health: Twenty-eight-five.

Health: Twenty-eight-five.

Teacher: The teacher found that some decimal students have different pronunciations. Which pronunciations are correct? Now listen carefully to the teacher. Can you read like a teacher?

Teacher: Can you pronounce decimals in your own words?

Student summary: The left part of the decimal point is read in the same way as the previous integer, and the right part of the decimal point only needs to read each number from left to right in order.

Teacher: Decimals are widely used in life. Let's look at other decimals in life.

The animals on land are African elephants. Its height can reach 8.5 meters and its weight can reach 5.25 tons.

Our animal is a giraffe, and its height can reach 5.8 meters.

The birds in the world are African ostriches, which can reach 2.75 meters in height, and an ostrich egg weighs about 1.5 kg.

Jellyfish is arctic chardonnay jellyfish, and the diameter of the umbrella cover can reach 2.5 meters.

(B) a preliminary understanding of decimals

(1) binary

Teacher: Look at the big screen. What did you learn from it?

Student: Divide one yuan into 10 parts, and each part is 10 cents.

Teacher: Can you point out 0. 1 yuan? (Students take the stage)

Only this can represent 0. 1 yuan? (Each corner can represent)

How to express 0. 1 yuan by fractions? Why?

Divide the US dollar into 10 parts, with one corner for each part. The score is110 yuan, and the decimal is 0. 1 yuan.

Teacher: What did 0.2 yuan say? What about 0.3 yuan? How about 0.4 yuan? ...

What about 0.9 yuan? Who wants some?

Divide one yuan into 10 parts, each part is 10 cents, of which nine parts are expressed as 9/ 10 yuan and the decimal part as 0.9 yuan.

Teacher: 1. 1 How many dimes is it? Why?

Health: 1 1, because 1. 1 yuan means one yuan and ten cents, that is, 1 1 minute.

Teacher:1.What about 2 yuan? 1.What about 3 yuan?

Teacher: The students are right. Let's take a closer look: when yuan is the decimal point, what does the decimal point on the left mean?

Health: Yuan.

Teacher: What does the first number to the right of the decimal point mean?

Health: refers to the angle.

Teacher: What do you think the second place should mean?

Health: meaningful.

Teacher: Let's see who can think. If it is not 1 yuan, what should be written in the integer part to the left of the decimal point? If it is not an angle of1,what should be written in the first place to the right of the decimal point?

(2) Metric system

Teacher: Not only do we often use decimals when expressing prices; We can also use decimals when measuring the length. Let's have a look.

This is a line segment 1 meter long. Now it is divided into 10 on average.

Teacher: How is this paragraph expressed in fractions? How to express it in decimals

1 decimeter is one tenth of a meter, or it can be written as 0. 1 meter.

Teacher: How about four copies, five copies, seven copies and nine copies? How many decimetres are they? How many meters is the score? How to express it in decimal? Take out the draft book and write it.

Teacher: What is the decimal point in the rice? What does it mean to the left of the decimal point?

Health: rice.

Teacher: What does the first number to the right of the decimal point mean?

Health: It means decimeter.

Teacher: What do you think the second place should mean?

Health: It means millimeter.

Teacher: So, students, have you found the relationship between decimals and fractions?

Health: A few tenths can be written as a few tenths. (In the case of real scores)

Third, consolidate and upgrade.

(a) the following decimal is () don't read zero.

a、80.6 B、2.60 C、3.05

(2) Look at the picture and show the black part with fractions and decimals.

(3) How to express it in meters only?

3 decimeters = () meters

1 m3 = () m

Fourth, the class summarizes.

Reflections on the Teaching of "Knowing Decimals" in Mathematics of Grade Three.

Understanding decimals is the teaching content of Mathematics (PEP), the standard experimental textbook of compulsory education mathematics curriculum. This part of the content once appeared in the eighth textbook, but it was moved to the sixth textbook in the new curriculum standard of People's Education Edition, which was carried out after senior one learned to express commodity prices with decimals. Because of the characteristics of this course, teaching should focus on lectures, and the learning of new knowledge is not very exploratory, and the thinking content is not too high. How to make such concept teaching "alive" on the basis of clarity and conciseness? How to explore the inquiry factors in such receptive learning and make it more meaningful? This is my concern. I mainly start from three aspects: First, starting from the life situation close to students, stimulate students' enthusiasm for learning.

Pupils, especially those in the middle and lower grades, are always full of interest and affection for the things around them. Therefore, I draw a picture of the situation around the teaching material, weave the problem situations reflected in the picture into interesting stories, and then use multimedia courseware to make students feel immersive, which can increase the interest of classroom teaching and make them devote themselves to learning activities.

Second, the introduction of mathematical culture into the classroom

The combination of "mathematical culture" and "mathematical teaching" conforms to the concept of curriculum reform. By letting students watch the historical short film of Decimal Point, they can experience the occurrence and development of mathematical knowledge, let them know the value and culture of mathematics, let them learn meaningful mathematics, stimulate students' intrinsic interest in learning and curiosity, let teachers let students learn, and let students become students themselves. While learning knowledge, cultivate students' interest in learning.

Third, organize the class in the form of games.

Listen to the teacher's description and guess what kind of animal it is through the math game. Change the boring classroom practice mode and adopt the form of guessing riddles to stimulate students' interest in knowledge and promote students' participation in games. Here, while the iron is hot, the teacher shows the height and weight data of each animal and asks the students to read these data, thus consolidating the decimal readings.

In a word, it has always been my teaching goal to make every student have the confidence and development ability to learn mathematics well, and to make him study happily and become a real master of mathematics learning.