Teachers should let students know the operation principle of fractional addition, know the calculation method of simple fractional addition and subtraction, and start with understanding the significance of fractional addition and subtraction. The following is a simple lesson plan for calculating the score of the first volume of the third grade of primary school, which I compiled, hoping to provide you with reference and reference.
Simple calculation of the first volume score in the third grade of primary school.
Teaching objectives:
1, knowledge and ability. Make students learn to calculate the simple addition and subtraction of fractions with the same denominator (denominator not exceeding 10). Through learning, students can initially realize that only fractions with the same denominator can be added or subtracted directly.
2. Process and method. Teaching in specific situations can arouse students' enthusiasm. At the same time, in the hands-on operation and reasoning training, students' mathematical language expression ability and logical reasoning ability are cultivated.
3. Emotion, attitude and values. Through discussion and communication, students can obtain calculation rules in independent inquiry, experience the formation process of knowledge, experience the role of the subject and gain a successful experience. Enhance students' experience and understanding of mathematics and cultivate students' sense of unity and cooperation.
Teaching focus:
Let students know the operation of fractional addition and subtraction.
Teaching difficulties:
Let the students understand that addition and subtraction can only be done if the denominator is the same. Solve the practical problem of simple fraction addition and subtraction.
Preparation of teaching AIDS and learning tools: wall charts, watermelon pictures and checkered cards.
Teaching process:
First, review the old knowledge.
1. Answer the following questions.
(1)4/9 contains () 1/9.
5/6 is 5 () /6.
(3) There are 7 ()/ () in 7/8.
(4) Two 1/9 are ().
2. Talk about the specific meaning of the score. 3/5 2/9 4/4
Second, create situations and introduce new topics
Show the contents of the situation map
Teacher: A watermelon is divided into eight parts on average. My brother ate 2 pieces and my sister ate 1 piece.
What do you suggest? Math problems?
According to the students' answers, the topic: simple calculation of scores-blackboard writing topic.
Third, explore new knowledge.
Show your textbooks and share the watermelon. (wall chart)
1, learning example 1: (1) Teacher: What information did you learn from the pictures?
(2) Teacher: How many watermelons did my brother eat? (blackboard writing 2/8)
Teacher: How many watermelons did my sister eat? (blackboard writing 1/8)
(3) Teacher: What math questions can I ask when I see 2/8 and 1/8 on the blackboard?
Health 1: My brother eats more than my sister;
Health 2: 2/8 is greater than1/8;
S3: These two fractions have the same denominator.
Health 4: How much did they eat this watermelon?
Health 5: How much did my brother eat more watermelon than my sister?
(4) Teacher's summary: The questions raised by the students are great! Will you solve it?
What are the results of the formula: 2/8+ 1/8 and 2/8- 1/8=?
Explore according to the addition questions put forward by students.
Students operate communication, image perception, and get a correct impression. The teacher made a tour.
Teacher: This student doesn't know whether the answer is 3/8 or 3/ 16? What? So what?
(5) Exchange feedback.
Teacher: Which team will report?
(1). Brother eats 2 portions, which is 2/8 of it, and sister eats 1 portion, which is 1/8, which is 3 portions, so it is 3/8.
②. Block 2 is 2/8, block 1 is 1/8, and block * * * is 3, so it is 2/8+ 1/8=3/8.
(6) The teacher sums up the reasoning, let the students speak for themselves first, and then the teacher guides them to express clearly and completely. "Two 1/8 plus 1 1/8 is three 1/8 is 3/8". (blackboard writing 3/8)
(7) Consolidate 3/5+1/5 = 4/9+3/9 = 2/5+3/5 =
Teacher: Observe the numerator and denominator in the formula. What did you find? Who can tell us how the addition of fractions with the same denominator is calculated?
Group discussion, report exchange (denominator same score subtraction: denominator unchanged, numerator added)
(8) Discuss the result of 2/8- 1/8.
① Block 2 is 2/8, block 1 is 1/8, and block 2 is more than block 1kloc-0/, so it is 2/8- 1/8= 1/8.
②. "Two 1/8 minus 1 1/8 equals 1/8 equals1/8". (blackboard writing 1/8)
③.4/7- 3/7= 8/9- 6/9= 6/6-5/6=
Teacher: Look at the numerator and denominator in the formula. What do you find? Who can tell us how to imitate addition to calculate the subtraction of fractions with the same denominator?
Group discussion, report exchange (subtraction of fractions with the same denominator: denominator unchanged, numerator subtraction)
2. Self-study example 2.
Fill in the blank on page 99 of the textbook.
3. Guide and induce the characteristics of fractional addition and subtraction.
(1) denominator is the same. Whether it is addition or subtraction, only fractions with the same denominator can be added and subtracted.
(2) Calculation method. The denominator is the same, but the numerator is added and subtracted.
Fourth, apply new knowledge to solve problems.
1, Exercise 23, Question 1.
Let the students observe the meaning of the picture first, and then talk about it when calculating and correcting it? The meaning of the diagram and the calculation process, the last one was not done.
2. Exercise 23, Question 2.
Ask the students to write the results in the book, instead of "1-4/7"
Verb (abbreviation for verb) class summary.
What did you learn in this class? Today, we learned the addition and subtraction of fractions with the same denominator. Be careful when calculating and pay attention to inspection.
Six, thinking questions: how many ways to fill in?
()/5+()/5=4/5 ()/9-()/9= 1/9
Seven, homework after class.
Exercise 23, question 3.
Eight, blackboard design
Simple calculation of fraction
2/8+ 1/8= 2/8- 1/8=
When the denominator is the same, the denominator remains the same, but the numerator is added and subtracted.
Simple calculation of the first volume score in the third grade of primary school; Model essay on mathematics teaching plan II.
Teaching content:
Teaching objectives:
Knowledge target
(1) Understand the principle of fractional addition and subtraction through observation.
(2) Can calculate the addition and subtraction of fractions with the same denominator whose denominator does not exceed 10 and the result does not need division.
(3) When the numerator and denominator of a fraction are the same, the fraction is 1, thus deepening the understanding of the fraction.
capability goal
Cultivate students' mathematical language expression ability and logical reasoning ability.
Affective goal
Strengthen students' awareness of cooperation and communication.
Teaching emphases and difficulties:
(1) Key point: Understand the operation principle of fractional addition, and be able to perform simple fractional addition and subtraction.
(2) Difficulties: Starting from understanding the meaning of fractions, understand the principle of addition and subtraction of fractions.
Teaching process design:
One. Stimulate interest introduction
Teacher: Have you heard the story about Pig and Bajie eating watermelon? Who will tell us?
Health: ...
Teacher: Zhu Bajie regrets this. One day, it found another watermelon. This time it has become smarter. Look, how many pieces is a watermelon divided into?
Health: ...
Teacher: Divide a watermelon into eight equal parts. (Courseware demonstration)
Teacher: What score can you find from the picture?
Health: ...
Teacher: How many of these scores are 1/8?
Health ... (The teacher shows several scorecards in turn)
Two. Teaching examples 1, 2, 3
1. Divide watermelons
Teacher: Can you guess how Pig and Bajie divide watermelons?
Health: ...
Teacher (showing the way to divide pigs) Look, greedy pigs. Master ate18 watermelon, brother ate18 watermelon, and brother Sha ate18 watermelon, but he ate 4/8 watermelon himself.
Find the problem
Teacher: Can you ask some math questions?
Teacher: Please take out your paper and pen and take notes.
(Student activities).
solve problems
Teacher: Tell everyone about your problem. (The teacher posts corresponding pictures according to the students' instructions.)
Teacher: Who can list the formulas?
calculate
Teacher: Today we will learn the simple calculation of scores.
A. Add
Teacher: Guess what 1/8 plus 1/8 is?
Health: ...
Teacher: Tell me what you think.
Health: ...
Two fractions with the same denominator are added, the denominator is unchanged, and the numerator is added.
B. subtraction
Teacher: What is 4/8 minus 1/8?
Health:
Two fractions with the same denominator are subtracted, the denominator remains the same, and the numerator is subtracted.
C. 1 minus one point
Teacher: Miss Li asked a question. How much is left after the pig ate a watermelon?
Health: ...
Teacher: Think about how to calculate?
Health: ...
Teacher's summary: subtract a fraction from 1, first write 1 as a fraction with the same denominator, and then subtract two fractions.
Three. Consolidation exercise
1. Fill it in.
2. Calculate: (and explain your thoughts)
3. Judgment: (Draw √ after the correct formula and × after the wrong formula)
3/8-2/8= 1/8
Four. Course summary
Today, we have a better understanding of fractions. It turns out that this friend can also add and subtract like integers and natural numbers we have learned before. Note that only the denominator is the same, you can add and subtract directly. What do you think should be paid attention to?
Five. arrange work
Exercise 23, questions 3, 4, 5, 6 and 7.
Simple calculation of the first volume score in the third grade of primary school; Mathematical teaching plan model wensan.
Teaching content:
Page 99 of the textbook ~ 100
Teaching objectives:
1, which enables students to calculate the simple addition and subtraction of fractions with the same denominator.
2. On the basis of understanding the meaning of fractions, make students learn to solve simple practical problems of adding and subtracting fractions.
3. Cultivate students' autonomous learning spirit, hands-on operation ability and problem-solving ability.
Key points and difficulties:
1, addition and subtraction of the same denominator fraction.
2. Decimal subtraction of integer 1 minus several fractions.
Prepare teaching AIDS and learning tools:
Watermelon pictures, CDs, checkered cards
Teaching process:
First, practice before class
1, fill in the blanks
There are ()1/42/5 ()1/54/8 ()1/85/9 ()1/9. Second, create situations and introduce new topics.
Show the content of the situation map, let the students observe and ask: What do you see?
What math problem do you want to ask?
Introduce topics according to the students' answers: simple calculation of scores, blackboard writing topics.
Third, explore new knowledge.
1, teaching scores add up.
1) Let the students use the learning tool to calculate: 2/8+ 1/8.
2) Student communication
Ask the students to say the calculation method.
3) Teachers demonstrate the process of 2/8+ 1/8 with teaching AIDS.
Let students know the arithmetic of fractional addition.
2. Subtraction of teaching scores
1) demonstrate the process of subtracting 2/6 from 5/6 with teaching AIDS.
2) Ask the students to tell the process of the teacher's demonstration.
3) Ask the students to list the formulas according to the process demonstrated by the teacher.
4) Question: How many 1/6 does 5/6 represent?
How many 1/6 does 2/6 stand for?
5) Guide students to say arithmetic and calculate.
3. Teaching Example 3
1) shows 1 wafers.
How much can the whole circle represent? What is the score?
2) Demonstrate the restoration process with teaching AIDS.
3) Ask the students to say the meaning of the demonstration.
4) Students list the formula 1- 1/4= according to the demonstration.
5) Let students calculate
6) Classroom communication
Let the students talk about the calculation process.
4. Students discuss first, and then teachers and students summarize the addition and subtraction calculation method of the same denominator score.
Step 5 practice
Textbook page 100, questions 1 2.
Fourth, homework
Textbook 10 1 page 1 and 2 questions.
Five, the class summary:
Today, we learned the simple addition and subtraction of fractions together. When calculating, you should clear your mind and pay attention to the investigation, especially when you encounter 1 MINUS several scores.