Article 1 Teaching objectives:
1. According to the specific situation, feel and know the mass unit ton, and know the weight 1 ton.
2. Master "1t = 1000kg" and make a simple conversion.
3. According to the specific situation, improve the ability to estimate the quality of objects and feel the connection between mathematics and real life.
Teaching emphases and difficulties:
1. Establish the concept of 1 ton.
2. Improve the ability to estimate the mass of objects according to specific conditions.
Teaching process:
(A) create a situation to guide the inquiry
1. Story introduction.
Teacher: Have you heard the story "Cao Chong called an elephant"? Who will tell you something? Other students must listen carefully and answer the questions after listening to the story! The teacher can then show a wall chart or multimedia picture and ask a classmate to tell the story of "Cao Chong is an elephant". )
Teacher: The story was told vividly and the students listened carefully. Think about it. How much does this elephant weigh?
Students may answer: it must be heavy, and it will be measured in grams, kilograms, or tons; Some people may also question: How many kilograms is that? )
The teacher leads the students to think: Do you think it is appropriate to explain the weight of elephants with the mass units grams and kilograms we have learned?
Ton is a large unit of mass, so what is 1 ton?
(Leading topic: 1 ton? )
(2) Explore communication and perceive new knowledge.
1.( 1) Which objects have a mass of 1 ton? The teacher uses courseware (or pictures) to show the situation map one by one, so that students can have a look and calculate.
350×3= 1050 (kg) Three buffaloes weigh about 1000 kg.
100×10 = 1000 (kg)10 barrel of oil weighs about1000 kg;
50×20= 1000 (kg) 20 bags of flour weigh about1000 kg;
25×40= 1000 (kg) 40 people weigh about 1000 kg.
(2) Group report.
According to the students' feedback, the teacher answers the blackboard: 1t = 1000kg, and introduces it in letters: 1t = 1000kg.
2. Get in touch with life and learn new knowledge.
(1) shows that many objects in life need to use the mass unit ton.
Ask the students to say the meaning of each picture, and the teacher adds.
(2) Ask students to give more examples from their lives and analyze them together.
(3) Comprehensive application, integration and expansion
After finishing the exercises in the book (rearranging the order of exercises), the teacher will patrol and guide the students with learning difficulties.
1. Fill in the appropriate units (grams, kilograms, tons): Question 3.
2. Fill it in. Question 1
4 kg = () g 3 tons = () kg
5000 grams = 2000 kilograms
18t= () kg () kg =6t
After the students finished speaking, the teacher showed the works on behalf of the students by physical projection and revised them collectively.
3. Students finish the second exercise independently, and then talk to their deskmates about their thinking methods.
Fill in ">"
8,000 kg, 8 tons, 4,500 g, 4 kg
3t ○ 3600kg
Students think independently and then give feedback. Ask several students to report their thinking methods.
4. Math stories.
(1) estimation.
Just now, the students listened to the story "Cao Chong called an elephant". Let's have a look. How many times did Cao Chong weigh it? (wall chart or multimedia presentation)
The stone on the ship was weighed eight times before it was finished. The record table is as follows:
How many times 12345678
Mass/kg 280220250300230250270350
Do you know how much this elephant weighs? Please look at the record sheet. Let's make an estimate first Give students time to think and then report to them.
(2) Ask the students to discuss: Why does Chong use this method as a symbol? Do you have a better idea?
How much does this elephant weigh? First calculate the weight of the elephant independently, and then exchange the calculation results in the group.
Each group reports the calculation results.
Collective feedback, reflection and summary
What did you learn from this course?
Chapter II Teaching Objectives:
The concept of 1, 1 ton was originally established by students' personal experience and experience.
2. Simple conversion between quality units can be carried out.
3. Cultivate students' observation, imagination and practical ability, cultivate students' sense of numbers and stimulate curiosity.
4. Initially cultivate students' ability to solve simple practical problems by using what they have learned.
Analysis of learning situation:
This course is an exploratory teaching based on the teaching of grams, kilograms and tons. 1 ton is very abstract. How to make students accurately perceive the weight of 1 ton has always been a problem that teachers have been puzzling over. It is the focus of this lesson to guide students to establish the quality concept of 1 ton. Therefore, I attach importance to learning and understanding mathematics from students' life experience and existing knowledge, and learn mathematics in connection with life.
The first link: teach how heavy 1 ton is, especially the practical significance of "1 ton" is the difficulty of teaching. Without corresponding experience, it is meaningless to simply remember the concept of 1 ton. So this class has designed an activity that students are willing to participate in and easy to participate in. All the students experienced 470g- 1kg and 200g-5kg- 10kg (1t) (very light-light-heavy-heavy). The whole process is interlocking, and students take the initiative to learn and learn easily from the game. Through the display of items in tons, why can't we bring such items to the site, and compared with the items we bring, we initially feel that the items in tons are very heavy.
The second link: the actual operation of how much a ton weighs is completed through group cooperation. Calculation, actuarial calculation and estimation are used by collaborators, so that students can cultivate their hands-on practice and cooperative learning ability through group cooperative inquiry activities or activities with realistic background, apply what they have learned to solve problems, experience the fun of exploration and the practical application of mathematics, and feel that mathematics is everywhere in life.
The third link: the group reports the results of cooperation, so that students can report the process of group calculation in accurate and complete language. Showing with courseware will bring greater impact to students visually.
Teaching focus:
Cultivate students' ability of observation, imagination and calculation, cultivate students' sense of numbers and stimulate students' thirst for knowledge.
Teaching difficulties:
Cultivate students' ability to use what they have learned to solve simple practical problems.
Teaching process:
Activity 1 Introduce the creation of situations and the introduction of topics.
First, create situations and introduce topics.
(1) feeling
Teacher: Let's play a guessing game. The teacher prepared four things, a bag of rice, a potted flower, a basketball and a shot put. Their weights are 470g, 1 kg, 200g, 10 kg and 5kg respectively. Who can take it and guess what it is?
Teacher: Can you tell me how you guessed?
Teacher: Can you pick up a lot of things?
Health 1: It's too heavy to carry.
Teacher: So how much does a ton weigh? Today, we are going to learn "How much does a ton weigh?" (Show the topic)
Activity 2: Group activities to explore practice.
Second, group cooperation, explore practice
(1), practice
Teacher: Teacher, here are four items. Please select the weight of an item and calculate how many such items weigh about one ton, that is, 1000 kg. And finish this practical assignment in class.
Teacher: Let's discuss it in the group first. Which one do you choose?
Health: 10 kg, 5 kg
Teacher: Why not choose these two? 470g and 1 kg 200g.
Health: It's not easy to calculate.
Teacher: The solution is always more difficult than the reality. Think about how to make the calculation simple. Which group is willing to challenge the difficulties?
Teacher: Encourage praise.
Teacher: Show me the requirements of teamwork. Please read aloud and explain the requirements one by one.
Student: Teamwork.
(2) Exchange feelings
Team work completed
Teacher: Which group would like to come up and exchange your ideas?
Health1:10kg10kg is100kg,100kg is100kg,
Teacher: Let's look at the big screen.
10/0 kg is 100 kg, 100 100 kg is 1000 kg,
Health: 2: 2 5 kg is 10 kg, 20 5 kg is 100 kg, 200 5 kg is 1000 kg is 1 ton.
Raw 3: 1 kg 200 g is regarded as 1 kg, 10 kg is 10 kg, 100 kg is 100 kg is/kloc-0.
Raw 4: 470g is about 500g, 2,500g is 1 kg, 20,500g is1kg, 2,000,500g is1000kg, and 2,000,500g is1000kg.
Activity 3 Practice Practice
Teacher: Show the courseware animation demonstration. If the teacher puts 20 basketballs in one basket, how many baskets can he put?
Activity 4 lecture summary
Teacher: Today, we passed the exam. Calculating and feeling the weight of a ton, there are more interesting mathematical knowledge in life waiting for us to explore.
Chapter III Teaching Contents:
Beijing Normal University Edition Grade Three Volume I 2 1 Page 22
Teaching objectives:
1. Knowledge objective: Know the quality unit "ton" and master the conversion formula of 1 ton = 1000 kg.
2. Capacity target: The mass of an object can be expressed in tons, and it can be converted from tons to other mass units.
3. Innovation goal: improve students' ability to understand abstract things, and improve students' ability to analyze and solve problems.
4. Emotional goal: to feel the connection between mathematics and real life.
Teaching focus:
Combined with the specific life situation, feel and understand the quality unit ton, understand the actual quality of 1 ton, and initially establish the quality concept of ton.
Teaching difficulties:
Master "1 ton =1000kg" and make simple conversion.
Teaching preparation:
Multimedia courseware.
Teaching mode:
Creating Situation-Perception and Exploration-Expansion and Extension
Teaching process:
First, create a situation
1, wonderful story
In the beautiful forest, the animal doctor wants to give the animals a physical examination. The elephant arrived first. Please guess its weight. The courseware demonstrates the process of weighing. ) Four good friends, bear, calf, pony and deer, also came from the other side of the river for physical examination, but they stopped when they reached the bridge. Do you know why? It turned out that on the bridge, Pony was ready to cross the bridge with everyone at the same time, but Bear pointed to the sign beside the bridge and said, "Weight limit is one ton". So they hesitated. Students, give me an idea! Can they cross the bridge at the same time?
2, group discussion, roll call answer.
3. Students can speak freely and guide the topic. How much does a ton weigh?
Then let's study how much a ton weighs first, and then help them cross the bridge, shall we?
Second, the exploration of perception
The courseware shows the situation map.
1. Guess: A buffalo, 1 bag of flour, 1 barrel of oil, what is the weight of a third-grade pupil?
2. Use a scale to verify the conjecture. (Courseware demonstration)
Step 3 give it a try
(1) Ask the students to carry a classmate weighing 25 kilograms.
(2) Take an oil drum with a mass of 50kg.
4. Take a look and calculate. Show the scenes one by one with courseware, let the students have a look and calculate.
Courseware demonstration
The mass of 1 barrel oil is 100 kg, and such 10 barrel oil just weighs 1 ton.
1 bag of flour is 50kg, () bag of flour is about1t.
The average weight of the third grade students in primary school is about 25 kilograms. () The human weight is about 1 ton.
A buffalo weighs 350kg, () A buffalo weighs about 1 ton.
Summary: Ton is the big unit of mass, 1 ton = 1000 kg; 1t= 1000kg (blackboard writing) The teacher stressed that tons are often used to measure the quality of heavy or large objects.
5. Tell me about it.
Through the above inquiry, we know how much 1 ton weighs. Which student wants to use tons to measure the quality of which objects in life? (Strengthen understanding)
(Students speak freely. )
6. Solve the problem: Can they cross the bridge at the same time (show the situation map)
(1) Now who can say whether they can cross the bridge at the same time and why?
(2) Who and who can cross the bridge at the same time? (group discussion)
Children have so many ways. It's really good. Niu Ge, they all crossed the bridge safely your way. They are very grateful for your help.
(3) If all our classmates visit this place, can we cross the bridge at the same time? Why?
Speak by name, and the teacher evaluates.
Third, the application of knowledge (fearless)
The first level: fill in.
4 kg = () g 3 tons = () kg
5000 grams = 2000 kilograms
18t= () kg () kg =6t
(After the grouping is completed, please report the method to several students. )
Level 2: fill in ">"
8000 kg 08 t 4500 g 04 kg 3t○3600 kg
Students think independently and then give feedback. Please report the method to several students. )
Level 3: Help Xiao Ming change his diary.
(Courseware shows diary and plays recording)
Today, the sun is shining. I went to the zoo with my parents. We first went to the supermarket and bought 1 gram of apples and 2 tons of pears, and 1 50 Jin of eggs. I saw an electronic scale in the supermarket. I'll go and weigh myself. Oh, my weight is 30 grams.
Arrive at the zoo. There are so many animals in the zoo. I estimate that a lion is about 350g, an elephant is quite heavy, at least 2g, and a talking parrot is about120kg. This buffalo weighs at least 338 tons.
After visiting the zoo, I went home happily.
(Students answer first, teachers evaluate)
Fourth, the class summary
What have you gained from this course?
blackboard-writing design
1 ton?
1 ton = 1000 kg;
1t= 1000kg
Tons are often used to measure the mass of heavy or large objects.
Tons are represented by the letter "t"