Template 1 of "Positive and Negative" Teaching Plan for the Fourth Grade of Primary Mathematics
Teaching objectives:
1, in the familiar life situation, further understand the meaning of negative numbers.
I will use the knowledge of positive and negative numbers to solve simple practical problems. Knowing that positive and negative numbers can cancel each other out solves the problem of the difference between positive and negative numbers.
3. Further cultivate students' ability to observe, analyze, ask questions and solve problems.
Teaching focus:
Further understanding that positive numbers and negative numbers represent quantities with opposite meanings can be used to deal with mathematical problems.
Teaching preparation:
Courseware and exercise paper
Teaching process:
First, the game thinks that positive numbers and negative numbers can cancel each other out.
1, teacher-student game
Teacher: Boys and girls, have you ever played the game of scissors, stone and cloth? Ok, let's play. Who wants to play with me?
(Teacher-student game, other students act as referees and are asked to take notes)
Teacher: Who will tell us your grades? Who do you think won?
Teacher: We must record the results of both sides in the competition. What do you think is a good way to record the results?
(revealing the topic)
Show the scoring rules: win a game with 1, draw a game with 0, and lose a game with-1
Contact with students' reality, create situations, experience the necessity of negative numbers in life, and mobilize students' autonomy and initiative in learning.
(Teachers and students * * * record the results of the competition)
Teacher: What's our score now?
Teacher: What do you think?
Health:+1 and-1 can cancel each other out?
Teacher: What do you mean by offset? What is the result of migration?
2. Life Games
Teacher: Do you want to play by yourselves? A team of two people will decide the outcome in three games, and one person must record the result.
(Student activities)
(Feedback the results of the competition)
3. Deeply understand the application of offset printing.
Teacher: How many games do you think the teacher will win if he wants to turn defeat into victory?
Teacher: What are their scores at this time? what do you think?
Teacher: Except for numbers like+1 and-1, +2 and -2, the result of cancellation is 0. Can you give an example of this?
Teacher: Can +5 and -3, -5 and +3 cancel each other out?
Summary: We can use positive numbers and negative numbers to represent two numbers with opposite meanings. By combining positive numbers with negative numbers, it can be calculated by cancellation.
Let students experience the meaning of positive and negative numbers in the game and understand the application of elimination method in the calculation of positive and negative numbers, so as to make the mathematical calculation of machinery interesting. Teachers only play the role of organizer, guide and collaborator in mathematics learning.
Second, find the difference between positive and negative numbers from the time axis.
(Courseware demonstration: Tiangong Ba Shen rendezvous and docking)
Teacher: What do you understand from this picture?
Teacher: Do you know the difference between the two meals of astronauts?
Teacher: Can you ask some new questions?
Closely connect with students' real life, create interesting and realistic situations, and use unique? Shenba, Tiangong-1 kiss in space? Scene, let students feel the meaning of negative numbers in life, and acquire mathematics knowledge through students' independent discussion, cooperation and exchange, and continuous exploration, give full play to students' dominant position, and make students realize that mathematics is applied to life, so as to achieve the purpose of applying what they have learned.
Third, comprehensively apply knowledge to solve the problem of positive and negative numbers.
Teacher: In addition to victory or defeat, life can also be expressed by pros and cons. Can you give an example of this?
Teacher: Positive numbers and negative numbers are widely used in life. As long as you feel them with your heart, they are around you.
Courseware demonstration: 1 1 year-old children's standard height is 150 cm. Let's write it down as 0. Think about your height. What should you record it as? )
(After students think, the whole class gives feedback)
Show me the form.
(1) Complete the form.
(2) Find the average height of this group of students.
Method 1: (150+145+157+155+148)? 5= 15 1 (cm)
Method 2: (0-5+7+5-2)? 5+ 150= 15 1 (cm)
(3) Compare the two methods
(4) Comparing the above data carefully, what new findings do you have?
(5) Know the number axis.
The consolidation of knowledge is unconsciously carried out in the situation and is hierarchical. The height of players is introduced from their own height, from actual height to positive and negative records, and then from positive and negative records back to actual height. When calculating the average height, the comparison of the two calculation methods shows the superiority of positive and negative cancellation, which makes students? Everyone learns valuable math? . In the comparison of the two groups of data, students actively think and explore, and feel the size and difference of positive and negative numbers. It can be said that the exercise design is interesting and exploratory. The introduction of number axis attaches importance to the cultivation of students' sense of number and forms a cognitive structure.
Fourth, class summary.
Teacher: What have you gained from learning this lesson?
"Positive and Negative" Teaching Plan Template 2 for the Fourth Grade of Primary Mathematics
Textbook content:
The position and function of teaching materials is that students have already known natural numbers, and on the basis of preliminary understanding of fractions and decimals, combined with familiar life situations, they have initially understood negative numbers. Through teaching, on the one hand, students can appropriately broaden their understanding of logarithm and stimulate their desire for further study; On the other hand, it also lays a foundation for students to further understand the meaning and operate rational numbers in the third period.
Teaching objectives:
(1) collect living materials and infiltrate the concept of negative numbers. Guide students to understand that positive numbers and negative numbers can represent two opposite quantities.
② Be able to read and write positive and negative numbers correctly, and know that 0 is neither positive nor negative.
③ Learn to express some practical problems in daily life with negative numbers. Have an intuitive understanding of the size between positive numbers, 0 and negative numbers.
④ Feel the role of mathematics in real life, and cultivate the good quality and practical application ability of exploring new knowledge independently.
Scholar analysis:
There are 62 students in this class, most of whom belong to the upper-middle level. Students have a certain level of cognition, strong curiosity and the ability to innovate and transfer knowledge.
Teaching strategies:
(1) Help students understand the meaning of negative numbers through colorful real life scenes. The generation and development of negative numbers stem from the needs of life. Therefore, teaching this lesson should pay attention to providing children with rich positive and negative phenomena in life, which can not only arouse students' interest in inquiry, but also make them feel that mathematics is in life and appreciate its infinite charm and value.
(2) Understand the demarcation point of opposites and? 0? The relationship. The difficulty of this lesson is that students can't easily understand the relationship between negative numbers, positive numbers and 0. How to break through the difficulties, intuitive teaching methods are the key. Among them, the observation of thermometer and the use of height map can effectively help students to gradually transition from intuitive to semi-intuitive to a more abstract understanding of their relationship.
(3) Carry out hierarchical inquiry activities to guide students to actively construct and develop their mathematical thinking ability.
Teaching process:
First, review.
1. Copy and paste the passbook details, and observe the expenditure (? ), deposit (+), what does the number in this column mean?
? +? On behalf of ()
? _? On behalf of ()
What they mean is ()
{Fill in the same or opposite content}
2. Get today's weather forecast online and record the temperature data of Harbin and Fuzhou.
Harbin () said? -
Fuzhou () said? -
They are based on () degrees, for example:+16? Means -+ 16? means
? 16? With what? 16? A quantity representing two () meanings.
Where is the temperature high and where is the temperature low?
Comparison:+16? ( )? 16? {Fill in >,< or =
3. with what? +? Quantity.
With what? -? Quantity.
+16 is pronounced-? 16 reading
4. Thinking: Is 0 a positive number or a negative number?
5. Collect negative numbers with different usages in life and tell me their meanings.
Second, teach new lessons.
1, check
(1)+500 means a deposit of 500. 500 means spending 500, which means (opposite) {fill in the same or opposite}
(2) Open the weather forecast chart.
Harbin (? 9? ~~~? 19? ) say? -Today, the temperature is between minus 9 degrees and minus 19 degrees, and the climate is cold, snowy and freezing. -
Fuzhou (1 1? ~~~~~6? ) say? -Today, the temperature is between-1 1 and 6 degrees above zero, and the climate is warmer, so there is no snow or ice. -
They are based on (0) degrees, for example:+16? Means MINUS 16 degrees? 16? It means negative 16 degrees.
+ 16? With what? 16? A quantity that represents two (opposite) meanings.
Where is the temperature high and where is the temperature low?
Supplement: Understanding the Representation of Number Axis
? 16 0 + 16
(3) Health report
With what? +? The number of-is called a positive number. +? figure
With what? -? The number of-is called a negative number. figure
+16 pronunciation-plus sixteen-? 16 pronounced? Negative sixteen-
(4) Is 0 a positive number or a negative number? Talk to the team members and discuss your ideas. Then report to the team.
Summary: 0 is neither positive nor negative, it is the dividing point between positive and negative numbers.
(5) Give examples of positive and negative numbers in life.
For example: profit and loss, the number of people getting on and off the bus, the number of floors above and below the ground, the fluctuation of water level, the distance in the opposite direction, etc.
Do the students have any difficult questions after learning this lesson? Ask students and groups to solve problems, and finally the teacher answers them in time.
Template 3 of "Positive and Negative" Teaching Plan for the Fourth Grade of Primary Mathematics
Teaching content:
Page 2 of the textbook, Example 1, Example 2, Example 3, do something and practice the first question 1-3.
Teaching objectives:
1. Know negative numbers in familiar life situations, understand the meaning of negative numbers, read and write positive numbers and negative numbers correctly, and know that 0 is neither positive nor negative. I can flexibly express some practical problems with negative numbers, and I can skillfully find the points corresponding to positive numbers, 0 and negative numbers on the number axis.
2. With the help of familiar life situations, experience the process of negative numbers and understand the meaning of negative numbers. Have the consciousness of combining numbers with shapes, and deeply understand the formation process of number axis.
3. Stimulate students' interest in understanding logarithms and feel the close connection between negative numbers and life.
Teaching focus:
To understand the meaning of negative numbers, positive numbers and negative numbers will be used to represent the opposite quantities in life.
Teaching difficulties:
Understanding quantities with opposite meanings and understanding of 0.
Teaching preparation:
courseware
Teaching process:
First, understand negative numbers.
(1) situational awakening
Students, as soon as class started, everyone did a set of opposite actions. Think about it. What is this?
Let's start with this class today. And vice versa? This topic begins to talk: there are many opposite phenomena in our life, such as the rising and setting of the sun every day, and people get on and off at the station.
Can you give a few more examples of this?
Follow this classmate's train of thought and continue to talk. What did you find when you entered the field of mathematics?
1. At the beginning of this year 15 transferred to the fourth grade, 15 transferred to the fifth grade.
2. In the activities of scissors, hammer and cloth, the male students won three times and the female students lost 1 time.
Uncle Li lost 3000 yuan in business in March and earned 8000 yuan in April.
How to express these quantities with opposite meanings in mathematical form? Let me see.
Requirements: concise, so that others can see it at a glance.
Report, there may be the following situations.
(1) direct expression (concise but unclear)
(2) Expressed in words (clear and not concise enough)
(3) Symbol representation (concise, clear and clear at a glance)
Summary: Now people use this form to distinguish quantities with opposite meanings.
(2) Know positive numbers and negative numbers.
Do you know what a number like this is called?
Like what? +3 Can you read?
For example (? 2) What about this figure?
How to read
Teacher's introduction: the plus sign is called the plus sign here, and the minus sign is called the minus sign.
Make a negative sign. Positive numbers and negative numbers represent quantities with opposite meanings.
Exercise: Read the following numbers.
- 100、+6.8、- 1.8、36
For simplicity, +36 can be written as 36. In other words, the plus sign can be omitted under normal circumstances. Teacher's blackboard writing
It is concluded that there are countless positive numbers and countless negative numbers, which are used to express.
Second, enrich new knowledge and introduce the history of negative numbers.
Students, where are we going from today? And vice versa? This word is about meeting a new friend, negative number. In fact, the understanding of negative numbers has a long history in China. Ancient people, faced with such problems, also came up with different methods. Do you want to know? Do you know page 4 of the courseware demonstration or study? )
How do you feel after listening to the introduction?
Next, let's go back to life and find out what negative numbers are around us. (blackboard title: negative number)
Third, the application in life
1. Understanding the negative number on the thermometer
A friend of mine likes traveling. These are several alternative cities he has chosen. I help him watch the temperature. Let's have a look.
(1) (Multimedia broadcast of urban weather forecast: Harbin-15-3℃, Beijing-5-5℃; Shanghai 0-8℃; Haikou 12-20))
It is very important to draw the conclusion that 0℃ is the dividing point between the temperature above zero and the temperature below zero, in other words, it is the dividing point between positive and negative numbers, so it is neither positive nor negative.
(Write 0 on the blackboard and classify positive numbers, negative numbers and 0 with the set circle)
Do you know how 0 degrees came from?
Introduction: Swedish astronomer Schell Qiu Si set the initial freezing temperature of water in natural state at 0℃.
(2) thermometer.
Do you use any tools to measure temperature in your life? (Courseware shows: thermometers commonly used in life)
Introduction: Celsius, Fahrenheit, each cell represents 1℃.
2. Negative numbers in the elevator
Which two buttons should I press when my uncle goes to the fifth floor for a meeting and my aunt goes to the second floor underground to get the car? (5、-2)
What is the dividing point between 5 and -2?
3. The altitude is negative
Mount Everest, the highest peak in the world, is 8844.43 meters above sea level. If this height is expressed as +8844.43 meters, then the height of Turpan Basin in Xinjiang, which is lower than sea level 155 meters, should be expressed as () meters, and the sea level height is () meters.
practise
If the geese fly 30 meters south for +30, then fly 50 meters north for ().
If the weight gain of 4kg is represented by +4, then-1.5 means ().
4. Negative numbers on the number axis
Example 3
Can you line them up after exercise? (emphasize who is the demarcation point and what direction is positive. Two statements)
It is pointed out that when the zero point (origin), positive direction and unit length are determined on a straight line, the number axis is formed. What you just said is the formation process of the number axis.
Now can you find their position after movement on the axis of numbers?
Finish the exercise
(2) If Xiaohua's position is+1 1 m, it means that she is heading for the () line () m. Point out the position of+1 1 and realize infinite number axis. )
(3) If Xiaogang first walks 5 meters east and 8 meters west, then Xiaogang's position is () meters.
(Hierarchical expansion)
5. Negative numbers on the sports field
Liu Xiang ran 1 100 meter hurdles in the semi-final of the 10th World Athletics Championships. At that time, the wind speed in the stadium was -0.4 meters per second. Do you know the meaning of wind speed of -0.4 meters per second?
Four. abstract
Today, let's get to know negative numbers and understand some functions of negative numbers in our lives. In fact, negative numbers have a wider range of uses in our lives, waiting for everyone to continue to understand.