1. 1 knowledge and skills:

Make students learn the calculation method of two-digit plus two-digit (non-carry addition) and be proficient in vertical calculation.

1.2 process and method:

Cultivate students' spirit of actively exploring knowledge and good habit of careful calculation.

1.3 Emotional attitudes and values:

Through students' experience of some phenomena and uncertainties, we can understand the close relationship between mathematics and daily life.

Emphasis and difficulty in teaching

2 1 teaching points:

Master the written calculation method of adding two digits (no carry addition), and can calculate correctly.

2.2 Teaching difficulties:

Master the written calculation method of adding two digits (no carry addition), and can calculate correctly.

teaching tool

Multimedia courseware.

teaching process

First, situational import

Teacher: Do the children want to visit the museum?

Health: Yes.

Teacher: Let's start with these students!

Second, explore new knowledge.

(1) 1. Observation chart. What mathematical information do you know from the chart? Students can show their answers in the form of tables.

2. According to this information, what math problems can you ask?

Communicate with the students in the group, and then report the teacher's selective blackboard writing example 1.

(2) Learning example 1

How many students are there in class (1) and who is the head teacher of this class?

1, students list the formula: 35+2.

Teacher: Why add?

As long as the students say it in their own words? A * * * is the number of students in Class 2 (1) and the number of teachers who lead the class. Just training students' language skills.

2.35+2= How to calculate? Try it with the stick in your hand.

Students do it independently.

Organizational report: how to calculate?

Health 1: I calculate 5+2=7 first, and then 30+7=37.

Health 2: I worked it out with a stick. First, I put three bundles and five sticks, and then two sticks. Five and two together make seven, plus the original three, seven makes 37.

Step 3 learn vertical style

Teachers and students take out the counter together, and the teacher explains the vertical writing while operating.

Teacher: What date do you think we should start? The children at the same table began to discuss.

Students talk about their own views.

Summary: In order to calculate carry addition in the future, we will start with you in the vertical calculation. The position is 5+2=7, 7 should be aligned in one position, and 3 in the tenth position should be written under the horizontal line and aligned in ten positions.

Group discussion on how to align when adding vertical calculation. Students express themselves in their own language.

It is clear that one bit to one bit and ten bits to ten bits can be summarized as the alignment of numbers on the same digit.

(3) Learning Example 2

1, courseware shows the situation map.

Teacher: Because the museum is far away, we have prepared a bus for the children that can take 70 people. Think about which two classes should be buses.

If Class Two (1) and Class Two (2) share a car, will Class Two (3) and Class Two (4) share a car?

Let's see if Class Two (1) and Class Two (2) can share a car. Please list the formulas. (blackboard writing: 35+32)

2. Students, can you calculate it in your favorite way?

Students are free to calculate, teachers patrol, and help students with learning difficulties in time.

Students may have the following algorithms:

Birth 1: mouth algorithm.

Student 2: Swing.

3. Cooperate to solve vertical problems

Teacher: Just now, the students worked out the result of 35+32 by oral calculation and swinging the stick. Great! Now, we can calculate vertically.

Summary: One-to-one and ten-to-ten can be summarized as digit alignment on the same digit.

Third, consolidate new knowledge.

Basic exercises

Textbook page number 12 ~ 13? Do it.

(2) Comprehensive exercises

Courseware shows exercises.

Summary after class

Through the study of this lesson, I learned that when calculating two-digit plus two-digit (carry-free addition), one digit should be aligned with one digit, ten digits should be aligned with ten digits, and the same digits should also be aligned.

Write on the blackboard.

Two digits plus two digits (no carry addition)

Little by little,

Ten to ten,

The same numbers should be aligned.

"Two plus Two" Teaching Plan (II) Teaching Objectives

1. Explore and master the calculation method of two-digit addition (no carry), and learn to calculate two-digit addition (no carry) vertically.

2, can use addition to solve some simple problems.

Emphasis and difficulty in teaching

Teaching focus

Master the counterpoint method of adding pen calculation and master the operation order.

Teaching difficulties

Do you understand? Para? The truth.

teaching tool

Multimedia courseware.

teaching process

First, review the old knowledge.

Teacher: Students, today we are going to learn the addition without carry within 100. First of all, let's review a knowledge we have learned before, that is, addition within ten.

The teacher randomly said the addition within ten, and the students quickly said the answer. In this way, after five minutes of repeated practice, students can review and consolidate the addition in the previous ten minutes, laying the foundation for learning new knowledge.

Second, learn new knowledge.

1, teaching example 1.

Teacher: Please turn to page 1 1 in the textbook and look at this picture.

By observing the pictures, organize students to discuss what information can be obtained from the pictures, and the teacher will comment and summarize.

Teacher: Please turn to page 12 of the textbook and see the example 1.

While reading the questions, students write on the blackboard: 1 How many students are there in Class 2 (1) and the teacher who leads the class?

Teachers guide students to examine questions, analyze the meaning of questions and find useful data.

Teacher: Now, who can tell me how to solve this problem?

According to the students' answers, the formula on the blackboard is 35+2=.

Teacher: Good. Now that the formula has been listed, how to calculate it? Can any clever students tell me?

Students speak actively, and teachers comment and summarize different algorithms.

Teacher: Good, everyone will use their own methods to calculate. Today, the teacher taught you a new method, which is column vertical calculation. Look at the blackboard.

Teacher: First of all, let's work out the problem by counting sticks. Look at the pictures in the book and discuss how to count them with sticks.

Summarize according to the students' discussion, focusing on the method of counting sticks, and calculate the whole ten sticks and less than ten scattered sticks respectively.

Teacher: Now we are learning how to write a vertical body. In fact, it is the way to express the number of sticks with numbers. Look at the blackboard, everyone.

The teacher wrote vertically on the blackboard:

35

+ 2

Teacher: Let's look at the blackboard and see what features this vertical style has. Let's discuss it together.

Summarize and comment on the students' discussion results, and summarize several characteristics of the vertical addition form: first, one for one, ten for ten; Second, the plus sign and the horizontal line are indispensable. The plus sign indicates addition, while the horizontal line separates the addend from the sum.

Teacher: Now that we know how to write vertically, let's see how to calculate it.

Explain while writing on the blackboard: starting from the unit, add up the units of the upper and lower numbers, write them under the horizontal line, add ten, and write the sum under the horizontal line. Pay attention to the calculation process of counting sticks to guide students to understand the vertical operation method of addition. Pay attention to emphasize that vertical calculation should start with one digit, then ten digits, and the sum obtained should also be aligned with the addend.

After explaining the example, I emphatically summarized the calculation method and writing standard of vertical addition without carry.

2. Consolidate the exercises.

Teacher: By now, everyone should be able to calculate the vertical non-carry addition of two digits plus one digit. Now, I will invite some students to do some exercises to see if everyone has learned it and if we can apply the newly learned knowledge.

Please ask five students to do the questions on the platform. Other students do it in their exercise books.

32+6= 24+3= 5+43=

2 1+3= 4+33=

Key points: the column is vertical, pay attention to writing norms and calculate correctly.

Comment on the works made by five students, praise the good ones, point out the wrong ones, correct them, and emphasize the correct writing norms.

3. Teaching example 2.

Teacher: Please look at Example 2 on page 13 of the textbook.

Blackboard:? Example 2. How many students are there in Class 2 (1) and Class 2 (1* *)?

Teachers guide students to analyze the meaning of questions and find useful data.

Blackboard writing formula: 35+32=.

Teacher: We have studied vertical addition before, but we used to calculate a two-digit number plus a one-digit number. Now both addends are two digits. How to calculate vertically? The students first try to calculate vertically in their exercise books.

Teachers summarize the calculation methods according to the students' longitudinal calculation. The teacher writes vertically on the blackboard:

35

+ 32

67

The vertical calculation method of two-digit plus two-digit non-carry addition column emphasizes several points: the alignment of each digit, the alignment of the plus sign and the horizontal line, and the addition from the single digit.

Summary after class

Teacher: I believe that students can also work out two digits plus two digits now. Let's practice.

Please ask four students to do a problem on the platform. Other students calculate in their exercise books.

33+43= 24+6 1= 53+22= 37+40=

Comment on what your classmates have done. Re-emphasize the writing standard and calculation method of vertical addition without carry.

homework

1, calculation problem.

10+ 19= 10+ 13= 14+2=

12+ 13= 15+24= 17+32=

13+43= 1 1+ 16= 16+22=

2. Application questions.

1, Xiao Ming read 13 yesterday and 12 today. How many pages has Xiaoming read these two days?

Cong Cong has 24 pieces of candy, which is obviously 5 pieces more than him. How many sweets are there in Cong Cong?

3. Dongdong scored 75 points in math, and Pepe scored 13 more than Dongdong. How many points did Pepe get?

Write on the blackboard.

First, align the unit bit with the unit bit, align the ten bits with the ten bits, and then add from the unit bit. Write the number added by the unit bit below the unit bit and the number added by the ten bits below the ten bits.