Teachers should be good at using lesson plans, drawing lessons from, compiling and adapting some questions as supplementary questions. In a word, it is very important to study the teaching plan carefully, which is of great benefit to improve the teaching quality. Next, I will bring you four operation teaching plans about fourth grade mathematics without brackets for your reference.

Fourth grade mathematics 1 teaching objectives four operation teaching plans without brackets;

Master the operation order of mixed expressions of addition, subtraction or multiplication and division without brackets.

Ability to ask questions and solve problems in problem situations.

Experience the exploration and communication process of solving practical problems, feel some strategies and methods to solve problems, and develop study habits such as careful examination of questions and independent thinking.

Teaching focus:

Summarize the operation order of mixed expression problems with only addition and subtraction or only multiplication and division.

Teaching focus:

Through examples, students are guided to summarize the operation order of only addition and subtraction or only multiplication and division, and the theoretical knowledge they have learned is applied to the solution of practical problems.

Teaching preparation:

multimedia courseware

Teaching process:

First, preparation before class

Do an arithmetic problem orally.

25+75 12×4 16+4+23 25×4×2

35+25 60-24 18+22 100-25- 10

Recall the operation sequence we learned before and tell us what you know.

Design intention: "Review the past and learn the new", so that students can recall that the operation order they have learned before is the rule of calculation from left to right, and lay the foundation for the study of this class.

Second, situational introduction

Display the theme map with multimedia. Tell me where it is depicted. What are people doing?

What math problem can you ask according to the information in the picture? How to solve it?

Design intention: elementary arithmetic should be used to record the steps or problem-solving plans of situational problems, which is another expression of situational problems. The elementary arithmetic problem is a digital situation problem, so it is more appropriate to start with the situation map.

Third, learn the operation sequence from left to right.

Only learn the operation order of addition and subtraction.

Multimedia presentation of "skating rink" 1: There were 72 people in the skating rink in the morning, 44 people left at noon and 85 people arrived. How many people are skating now?

Teacher: What are the known conditions of this problem? What does each condition mean?

(While students are thinking and communicating, multimedia courseware shows the known conditions and their significance)

Teacher: How many people are skating now? , how to calculate?

(student continuous computing, packet switching solution)

Classroom communication

Methods 1: Step by step.

72-44=28 (person)

28+85= 1 13 (person)

Method 2: Column synthesis formula

72-44+85

Teacher: Who can tell us what should be counted first in this comprehensive formula? What is it?

Communicate according to the students' answers and show the calculation process.

2. Do it: What is the operation order of each question?

100+30- 16

38+65-45

120-80+72

Teacher: What are the characteristics of the operation sequence of the above formulas?

Student discussion summary: In the formula without brackets, if there is only addition and subtraction, it should be calculated from left to right. )

Design intention: To abstract and summarize the operation rules from the realistic problem situations, which is convenient for students to understand and apply, and also convenient for students to analyze and compare different problem-solving methods based on existing knowledge and experience.

3. Only learn the order of multiplication and division.

Multimedia display of "ice and snow" situation map and example 2: "ice and snow" received 987 people in 3 days. According to this calculation, how many people are expected to receive in six days?

Teacher: What do you mean by "according to this calculation"?

Teacher: Think about it. How to list the formulas? Talk about the solution of your formula in the group?

(Students calculate continuously and exchange ideas for solving problems in groups)

Classroom communication

987÷3×6 6÷3×987

(According to students' communication, show the formulas of two kinds of problem-solving ideas, and help students understand the problem-solving ideas of the two formulas in the form of multimedia display)

Teacher: What should the comprehensive formula calculate first? What is it?

Design intention: pay attention to the diversity of problem-solving strategies. This will promote the development of students' thinking flexibility and improve their ability to analyze and solve problems.

4. Made: a box 12 bottle of orange juice. 48 yuan, Fangfang wants to buy three bottles. How much will it cost?

(Students do it independently. If you can only list the step-by-step formula at first, list the comprehensive formula according to the step-by-step formula to guide students to use the comprehensive formula as much as possible in the future; If someone lists the comprehensive formula, let the students talk about the operation order and pay attention to the format of recursive equation calculation. )

Teacher: What are the characteristics of the operation order of these questions?

Student discussion summary: In the formula without brackets, if there is only multiplication and division, it should be calculated from left to right. )

Design intention: The purpose of choosing to solve practical problems in teaching is to avoid treating elementary arithmetic problems as simple calculation problems, causing the illusion that mathematics has nothing to do with daily life and causing students to find no examples of using elementary arithmetic to help solve daily life problems.

Fourth, consolidate practice.

Rewrite it into a comprehensive formula according to the following step-by-step formula.

150+33= 183 183-75= 108

274-52=222 222+63=285

200÷4=50 50×3= 150

28×2=56 56÷7=8

Judge and correct mistakes.

155-34+46 240÷40×3

= 150-80 =240÷ 120

=75 =2

Design intention: Let students think independently, analyze and complete exercises, strengthen the connection between step-by-step formula and comprehensive formula, and ask students to explain the reasons. Cultivate students' comprehensive ability to use knowledge, strengthen the connection between mathematics and life, and make students form the good habit of finishing their homework carefully and writing neatly.

Summarize thinking.

Teacher: To sum up, what are the characteristics of the formula learned today? What is their operation sequence?

(In the formula without brackets, if there is only addition and subtraction or only multiplication and division, it should be calculated from left to right. )

Teacher: What do you think of your study today?

Four operation teaching plans without brackets in fourth grade mathematics II. Teaching objectives

1. Feel the necessity of specifying the operation order when solving practical problems, further master the operation order of addition, subtraction, multiplication and division and calculate correctly.

2. Experience the process of exploring and communicating to solve practical problems, and feel some strategies and methods to solve problems.

3, in the process of solving practical problems, cultivate the ability to ask and solve problems.

Second, the focus and difficulty of teaching

1. Teaching emphasis: feel the necessity of operating sequence, ask questions and solve problems accurately.

2. Teaching difficulties: mastering strategies and methods to solve problems.

Gather wisdom to prepare lessons.

(1) basic training

24×5= 32÷4= 8+27= 900÷3=

60÷4= 72-44= 45×3 = 85+28=

Put eight hexagons with a stick to solve the problem. How many sticks do you need?

(B) new knowledge learning

Typical example

Example 2 "Ice and Snow World" received 987 people in three days. According to this calculation, how many people are expected to receive in six days?

1. Observe the topic map and ask questions according to the conditions.

2. Group communication. According to the information in the picture, what problems can you ask and how to solve them? (Guide students to understand the meaning of "this calculation")

3. Grasp the connection between old and new knowledge and transfer learning knowledge by analogy.

4. Student report. Guide students to synthesize formulas and say the meaning of each step.

5. The teacher guides the students to solve problems in two ways with the line chart.

6. Teaching methods: Line drawing, sketch and other methods can be used to help us sort out the problem-solving ideas and ensure the accuracy of problem-solving.

Summary If there are no brackets in an expression, you only need to calculate addition, subtraction, multiplication and division from left to right. When solving problems, you can use methods such as drawing line segments and sketching to help you sort out your problem-solving ideas.

(3) Consolidate exercises

Basic exercises 1. Write the calculation results directly.

37+ 12-20 24÷6×7 90-52+28

6×2÷4 32÷8×5 48- 13+5

2. Draw the calculation order of the following questions and calculate any two questions.

192+8+ 157 45×30÷54 290-68+95 1 600÷50×90

143-45-57 24×5÷30 434÷7×8 240÷20÷4

3. Doctor Woodpecker (correct judgment)

850÷25×2 345- 164+36

=950÷50 =345-200

= 19 = 145

1, textbook P 5, 1, the library has 98 story books. Today, 46 books were lent out and 25 books were returned. How many story books are there in the library now?

Improve the exercise 1, calculate first, and then make a comprehensive formula.

240÷ 12= 236+70= 237+263=

125× 14= 1750÷25= 25×36=

20+ 1750= 943-306= 900-500=

2, column comprehensive calculation

What's the difference between (1)4 divided by 900 minus 224?

(2) What is the sum of 504 plus 140 divided by 28?

(3) Three times of a number 12 is less than 60. What is this number?

3, textbook P8 exercises 1 4,

4. What math questions would you ask? Parallel computing.

Xiao Zhang has 8 yuan 10 yuan. Xiao Wang has 18 2 yuan. ?

Outward bound exercise 1. Solve the following problems in two ways: (only formula is needed, no calculation is needed)

(1) During the Spring Festival, Xiaolan bought a batch of extra-curricular books for her little library with lucky money. The small library has 2 bookcases, each with 6 floors, each with 15 books. How many books are there in Xiaolan's library now?

(2)

3、

(D) Teaching effect evaluation (quiz)

1、39+46- 18= 49÷7×4= 73-45+27= 18×4÷9=

2, a children's coat 48 yuan, a pair of pants is cheaper than a coat 9 yuan, a skirt is more expensive than pants 5 yuan. How much is this skirt?

Four operation teaching plans without brackets in the teaching goal of mathematics 3 in grade four

1. Let students feel that using brackets is a strategy to solve practical problems.

2. Make students master the operation sequence of two-level operation (including brackets) and calculate correctly.

3. Cultivate students' habit of thinking independently and considering problems from different angles.

Emphasis and difficulty in teaching

Make students master the operation order of two-level operation (including brackets) and calculate correctly.

teaching tool

courseware

teaching process

First, review old knowledge and introduce new lessons.

1, oral calculation

120+30-60 8×5× 10

20+30÷3 120÷3×5

12×5-40÷2 150- 100÷5×4

100×(38-3 1)

Second, learn new lessons.

1. Show the wall chart and Example 4 (after writing on the blackboard)

1. Guide students to read the questions carefully and understand the meaning of the questions. In particular, every 30 tourists need a cleaner. How much do 60 tourists need? What about 90 tourists?

2. Analyze the quantitative relationship in the problem, start with the problem and think independently about what you want first and then what you want.

3. Exchange ideas to solve problems (lead to the second solution).

4. How to make the above formula into a formula? (After writing on the blackboard)

Q: The meaning of each step formula.

For the operation with brackets, what is first, then what.

2. practice P 1 1.

3. Example 5. (After writing on the blackboard)

Please mark the operation sequence number in the formula in the book. Two students are acting on the board, and after evaluating each other at the same table, they calculate independently and revise collectively.

The teacher asked: What are the similarities between the two small questions? What is the difference? Why are the two questions different?

Finally, tell your deskmate what you want first, then what you want, and finally what you want.

Teacher: Addition, subtraction, multiplication and division are called four operations, and the order of the four operations is summarized in the form of group cooperation.

The teacher arranges four operation sequences of blackboard writing. (After writing on the blackboard)

4. Practice P 12 and do 1 and 2 questions.

5. Class summary: What have you gained from this class?

homework

Finish the exercises after class.

Teaching objectives:

1. Understand the meaning of exact numbers and divisors with examples in life.

2. Master the rounding method to find the divisor of a number, and learn to use the rounding method to omit the mantissa after "10,000" or "100 million" and find its divisor.

3. Guide students to observe and experience the close relationship between mathematics and life, and cultivate students' spirit of active inquiry and consciousness of applying mathematics.

Teaching emphasis: We can correctly judge the divisor and exact number in life, and will use the method of "rounding" to find the divisor of a number.

Difficulties in teaching: Flexible use of "rounding" method to find the approximate value of a number.

Teaching preparation: courseware

Teaching process:

First, introduce a conversation

Teacher: I am thirty-five years old and have spent more than ten thousand days and nights.

Think about it: which of the two figures introduced by the teacher is more accurate? Why?

Guide students to speak freely. Teachers give real-time guidance in the process of students' communication, and guide students to conclude that 35 years old is more accurate, and more than 10 thousand days and nights are an approximate number.

Introduction: Today, in this class, we will learn the divisor together. (blackboard writing topic)

Second, communicate and enjoy.

(a) know the approximate figures

1. The courseware shows the situation diagram of Example 6 on page 2 1 of the textbook.

2. Preliminary perception.

Ask students to read the information in two situations and think about it in combination with the content in the situation: if you were asked to divide four underlined numbers into a point, how would you like to divide them? Why?

After the students think independently, the teacher organizes communication.

3. Deepen understanding.

(1) Thinking: Do you know which numbers are approximate?

On the basis of students' thinking and communication, the teacher made it clear that 2.2 million and19.02 million are approximate values; The number of some things in life sometimes does not need to be expressed by an exact number, but only by a number close to it, and such a number is a rough number.

(2) Let students talk about the divisors in life with concrete examples.

(2) Find the divisor of a number

1. Courseware shows the textbook page 2 1 Example 7 "Population Statistics of a City in 20 12".

Ask the students to observe the data in the table and read the numbers.

2. Find the approximate value of a number with the help of straight line understanding.

(1) The teacher shows a straight line:

380 thousand 390 thousand

(2) Draw points representing the number of men and women on a straight line.

Question: Where are the points on the straight line that represent the number of men and women? Draw them separately.

The students try to count on a straight line in the textbook.

Teachers predict students' completion results:

380,000 384,204 386,685 390,000

(3) Observe the straight line and explore the method of finding the divisor.

Question: Observe that the numbers 384,204 and 386,685 are on a straight line. The distance between them is tens of thousands.

After students think independently, communicate in groups. The teacher toured to understand the students' communication.

Organize class exchanges.

Encourage students to express their opinions, students may have the following two ways of thinking:

Method 1: 384204 is on the left of 385000, close to 380000; 386685 is on the right of 385000, close to 390000.

Method 2: 4. 384.204 million, less than 385,000, close to 380,000; 3,866.85 million is 6, which is larger than 385,000 and close to 390,000.

Teachers should give affirmation to both methods.

3. Introduce the method of "rounding".

(1) The teacher introduced the "rounding" method to find the approximate value of a number.

To find the divisor of a number by "rounding", we should keep the number to a certain place as required and omit the mantissa after it. If the number of digits in the mantissa is 4 or less, all digits in the mantissa are rewritten as 0; If it is 5 or greater, add 1 to the first digit of the mantissa, and then rewrite each digit of the mantissa as 0.

(2) Find the approximate number of men and women by rounding.

Let the students write independently first, and then organize the report exchange. In the communication, let the students talk about how to find their approximate value by rounding.

The teacher reports on the blackboard according to the students:

384204≈380000

386685≈390000

4. Complete page 22 of the textbook "Give it a try".

(1) courseware shows the topic.

(2) Let students think independently and exchange reports in groups.

(3) Question: How to rewrite a number into a divisor in units of "10,000" or "100 million"?

Students exchange and discuss, and the teacher summarizes.

Third, the feedback is perfect.

1. Complete the exercise on page 22 of the textbook.

The problem is to distinguish accurate figures from approximate figures in combination with life conditions. Among them, 56785 and 16 17 are exact numbers, and 460000000, 200000 and 3000000 are approximate values.

2. Complete Exercise 4 No.5 5~ 10/0 on page 24 of the textbook.

Students report collectively after they finish independently.

Fourth, reflection and summary.

What have you gained from learning this lesson? What other questions are there?

Teaching requirements of four operation teaching plans without brackets in fourth grade mathematics;

Enable students to further master the calculation formulas of parallelogram, triangle and trapezoid areas, and correctly calculate their areas.

Teaching focus:

Familiar with the actual measurement knowledge, can correctly apply the learned knowledge and solve some practical problems.

Teaching process:

First, basic exercises

1. Page 145 ④.

3.5+7.6 12-6.2-3.8 7÷0.25 5.6× 1.0 1

1.7+0.4 3+3.3 5.4-2.5- 1.47 2.8÷0.8

( 1.25+0.36)×0.2 0.99+ 1.8 2.56-0.37

500×0.00 1 3.2÷ 1.6 3.9+2.03 7.5×2.5×4

0.36÷ 12 0.75×4 4.9÷3.5 1.2×0.4+ 1.3×0.4

2. 14-0.9 6.25×0.8

Second, review the guidance.

1. Relevant knowledge of actual measurement

(1) Students already know that when measuring the distance between two distant points on the ground, a straight line must be determined first. What can I do to determine this straight line?

On the basis of the students' answers, let the students look at the illustration on page 86 and how to do it.

(2) When walking, you must first know the length of your step. How can I know the length of my step?

According to the students' answers, let the students see how to calculate their average step size on page 87.

(3) Students do Exercise 20 independently, Question 7. Ask the students to say what they think when correcting collectively.

2. Calculation of parallelogram, triangle and trapezoid area.

Exercise 20, question 5.

(1) What are the numbers? Then measure the data needed to calculate their areas and calculate their respective areas.

(2) What do you find by comparing their areas?

(3) On the basis of students' speeches, it shows that these four figures have different shapes, but their areas are equal. Their height is equal to 2 cm, and the bottoms of rectangles and parallelograms are 1.5 cm, so their areas are equal; The sum of the top and bottom of the trapezoid and the bottom of the triangle is 3 cm, which is twice as large as the bottom of the rectangle and parallelogram. However, according to the formula for calculating their area, if the sum of the bottom and the height is divided by 2, then their area is equal to that of rectangles and parallelograms.

Third, classroom exercises.

1. Exercise 20, question 6.

Students calculate independently and modify collectively.

2. Exercise 20, Question 9.

After the students expressed their opinions, the teacher emphasized that the area of a triangle is determined by its height and bottom. If the base and height of two triangles are equal, their areas are equal; If two triangles are equal in height and unequal in bottom, then their areas are not equal.

Fourth, homework

1. Exercise 20, question 8.

2. Students who have spare time to study can do exercise 20, question 1 1, and think about questions.

Four operation teaching plans without brackets in fourth grade mathematics;

Comprehensive practical activities designed by ourselves according to the relevant contents of measurement.

Teaching objectives:

1, learn the measurement methods such as step measurement and visual inspection, understand the measurement methods such as light side measurement, shadow measurement and rope measurement, and carry out actual measurement.

2. Develop spatial concept and abstract generalization ability in solving practical problems in life.

3. Use what you have learned to improve your ability to solve practical problems and calculate.

4. The application of experiential mathematics in real life.

Teaching preparation:

Courseware, meter ruler, tape measure, etc.

Teaching process:

First, ask questions.

Teacher: We know the length units of meters, decimeters and centimeters, as well as their approximate lengths, so today we are going to make actual measurements with what we have learned. What measurement knowledge do we need to know before measurement? For example: measuring tools, measuring units, measuring objects, measuring methods and so on.

Students mentioned that you should use a ruler when measuring and use meters, decimeters, centimeters and other length units when recording the measurement results. )

Second, the activity procedure

1. Preparation activity: Show people's courseware for measuring some buildings.

Step 2 arrange activities

Teacher: We have mastered the knowledge of measurement. Let's ask the students to choose an object you want to measure in combination with real life and choose the appropriate measurement method for actual measurement.

Measurement requirements

(1) are measured in groups.

(2) Each group should make records on the activity card.

3. Provide students with "measured activities" cards.