Teaching plan of simple decimal addition and subtraction in the third grade mathematics of People's Education Press.

Teaching objectives of simple decimal addition and subtraction teaching plan (1)

1, so that students can learn to calculate the addition and subtraction of a decimal.

2. Gradually cultivate and improve students' mathematics learning ability through inquiry activities.

Emphasis and difficulty of teaching

Addition and subtraction calculation of one decimal place. Addition and subtraction. Decimal alignment.

teaching tool

courseware

teaching process

First of all, the situation is introduced.

Show me the main picture. (Slide projection or wall chart)

Please say, what do you see? What information did you get? Students go to the store to buy school supplies. From the figure, we can know the unit price of some commodities: pencil case 6.8 yuan, schoolbag 25.8 yuan, exercise book 2.6 yuan, eraser 0.5 yuan, pencil sharpener 0.8 yuan, pencil 0.6 yuan, fountain pen 1.2 yuan).

Second, experience exploration and gain new knowledge.

1, Teacher: The students learned the addition and subtraction of integers and the simple addition and subtraction of fractions. Now, we know the decimal again. Please guess what else we should learn about decimals.

The students answered, and the teacher wrote on the blackboard: Simple decimal addition and subtraction.

2. Teaching Example 3

1 pencil sharpener and 1 pencil, how much is a * * *?

(1) How much is the pencil sharpener? How much is this pencil?

How much is a * *? What method must be used to calculate? (Supplementary)

What do you think? what do you think?

Ask students to explore methods and try to calculate.

After discussion and communication, students generally have two calculation methods (one is to calculate by angle; The other is to use yuan as the unit and calculate directly with decimals).

After the students report the calculation results, the teacher guides all students to explore the method of direct calculation with decimals.

(3) Key analysis.

① Verification answer: 1.4 yuan = 1 yuan jiao, and the result is correct.

② Observation formula:

Function 1: decimal point alignment. (Number alignment equivalent to integer addition)

Here, not only the decimal points of two addends are required to be aligned, but also the decimal points should be aligned with the decimal points of addends.

Feature 2: The calculation process and method are the same as integer addition.

3. Teaching example 4.

(1) Ask a question: How much is a pencil sharpener more expensive than a pencil?

(2) Query calculation and direct calculation with decimals.

0.2 yuan =2 Angle, 8 Angle -6 Angle =2 Angle, the result is correct.

Example 4

How much is a pen more expensive than a pencil?

(1) require students to calculate directly with decimals.

② Try to calculate and report the results. (Show demo board)

1.2-0.6=0.6 yuan

(3) Talk about the calculation points.

Two points: one is decimal point alignment; The second method is subtraction, which is the same as integer subtraction.

4. Course summary

(1) The teacher explained the simple situation of directly using decimal calculation, which is widely used in daily life, and made students realize the importance of mastering decimal calculation.

② Students explain the main points of decimal calculation.

Third, classroom activities.

Textbook page 96 1? Do it.

(1) The problem is fractional addition. Students do it independently.

Question (2) has knowledge of both decimal addition and decimal size comparison.

Question (3), let the students ask their own questions, and guide them to put forward simple addition and subtraction calculation problems and calculate them.

2. Supplementary questions.

In the photo? Give you 60 cents? Guess: How much did Xiaohong give to the shop assistant? Maybe, what did she buy?

Inspiration: find out the amount of money to buy goods with a mantissa of 4 cents.

Fourth, class assignments.

Exercise 22, Question 1-3.

Verb (abbreviation of verb) course summary

What did we learn in this class? What have you learned?

homework

Finish the exercises after class.

Simple decimal addition and subtraction teaching plan (2) teaching objectives

Knowledge and skills

Make students further understand the meaning of decimal in specific situations, understand the simple arithmetic of decimal addition and subtraction, and master the calculation method, which will correctly calculate the addition and subtraction of one decimal.

② Process and method

Make students experience the process of understanding arithmetic and exploring algorithms, and cultivate their ability of induction and knowledge transfer.

③ Emotional attitude and values

Make students feel the close connection between mathematics knowledge and real life.

Emphasis and difficulty of teaching

Teaching emphasis: understand the simple arithmetic of decimal addition and subtraction; Mastering the calculation method will correctly calculate the addition and subtraction of a decimal.

Teaching difficulty: understand the simple operation of decimal addition and subtraction.

teaching tool

courseware

teaching process

1. View import

Show me the calculation problem.

Teacher: How do you calculate it? What should I pay attention to in vertical calculation of integer addition and subtraction?

The vertical calculation of integer addition and subtraction should pay attention to: the same number of digits should be aligned; add

When one of us is over ten years old, he will enter the next world? 1? ; In subtraction, which one is not enough?

Want to retire from the last one? 1? .

Today we are going to learn simple decimal addition and subtraction. Blackboard writing: simple decimal addition and subtraction

Explore new knowledge

Show pictures in courseware

What mathematical information do you get from observing the pictures? What meaningful math problems can you ask?

Answer by name. Selective blackboard writing:

How much does it cost to buy a pencil sharpener and a pencil without an eraser?

How much is a pencil sharpener more expensive than a pencil without an eraser?

Teacher: Can you solve these problems? How to form?

How much does it cost to buy a pencil sharpener and a pencil without an eraser? Speak your mind.

0.8 yuan =8 jiao.

0.6 yuan =6 jiao.

8 Angle +6 Angle = 1 Yuan 4 Angle = 1.4 yuan.

How much is a pencil sharpener more expensive than a pencil without an eraser?

Name your classmates.

Non-abdication subtraction

0.8 yuan =8 jiao.

0.6 yuan =6 jiao.

8 Angle -6 Angle =2 Angle =0.2 yuan.

? 2? Why did you write it here?

The teacher wrote the students' questions on the blackboard again.

Explaining abdication subtraction

Teacher: Is there a problem? Can you calculate in decimals?

1.2-0.6=

Teacher:? 2? Subtract? 6? What if the reduction is not enough?

Attached answer:

1.2-0.6=0.6

Teacher: How to calculate the vertical decimal addition and subtraction?

Summary: When calculating the addition and subtraction of decimals vertically, first align the decimal points of each number, and then calculate according to the law of integer addition and subtraction. The decimal point in the obtained number should be aligned with the decimal point on the horizontal line.

Teacher: Try to solve the math problem you just asked yourself.

Students answer questions in groups, and teachers patrol and give key guidance.

Show pictures in courseware

Teacher: Look at the picture. What kind of questions can you ask?

How much cheaper is brainstorming than campus science fiction?

Xiao Ming has 10 yuan on him. He bought one of these two books. Did he bring enough money?

Attached answer:

6.80-3.40=3.40 yuan

6.80+3.40= 10.2 (yuan)

10.2﹥ 10

He didn't bring enough money.

Lily brought 10 yuan and bought two different drinks. How much is left?

3.6+2.8=6.4 yuan.

10-6.4= 3.6 (yuan)

A: There's 3.6 yuan left.

Teacher: Decimal addition and subtraction When decimal points are aligned, the same numbers will be aligned.

3. Classroom exercises

See who does it quickly and correctly.

7.74-5.85= 9.35-4.74=

38.63-3.42= 1. 16+4.77=

8. 17-5.26= 2.26-0.86=

4.93+4.75= 76.55+4.68=

Attached answer:

7.74-5.85= 13.59 9.35-4.74= 10.09

38.63-3.42=35. 1 1 1. 16+4.77=5.93

8. 17-5.26=2.9 1 2.26-0.86= 1.4

4.93+4.75=9.68 76.55+4.68=8 1.23

Show pictures in courseware

Name and tell me how you calculated it.

Teacher: When you go home, ask your parents to measure your height. When you go back to school, compare the heights of other students and see who is taller.

4. Consolidate sales promotion

Show pictures in courseware

Attached answer:15.4+2.1+2.3 =19.8 (kg)19.8 ~ 20, so we can't take the boat together.

Teacher: What questions will you ask?

How much are roses and carnations?

How much is a rose more expensive than a carnation?

Attached answer: 2.2+0.6=2.8 (yuan) 2.2-0.8= 1.4 (yuan)

Ask and answer math questions.

Show pictures in courseware

How much is a dress?

Attached answer: 27.9+54.9=82.8 (yuan)

Summary after class

One question: What did you learn in this class?

What did you learn in this class?

Summary of teachers and students