5.两位数加两位数（进位）课件配套优秀公开课教案设计

课

题

Carry addition of 2-digit number and 2-digit number (1) 2018年 5 月 7 日 第 10 周 星期 二

授课时间

教学内容

Carry mental addition of 2-digit number and 2-digit number. 1.

To enable the students to understand the methods of carry addition. 教学目标

2.

To enable the students to do the carry mental addition correctly. 3.

To enable the students to solve the problems about carry mental addition. 1.

The students can understand the methods of carry addition. 教学要求

2.

The students can do the carry mental addition correctly. 3.

The students can solve the problems about carry mental addition. 1. The students can understand the methods of carry addition. 教学重点

2. The students can do the carry mental addition correctly.

教学难点

课前准备

教 学 过 程 与 方 法

原 有 的 教 学 设 计 与 方 法

Step 1 Lead in.

T: Today we will go to the zoo. Are you ready? Let’s go!

Step 2 Presentation. T: The zoo is so far that we can’t walk to the zoo. We can by bus.

There are 24 boys and 16 girls in our class. Here comes the bus. There are 42 seats on the bus. Can all the students get on the bus? (The teacher guides the students to write the number sentence: 24+16) T: How to get the answer? Maybe we have different ways to solve the problem. Possible answer: 24

+

16

20

4

10

6 24 can be divided into 20 and 4. 16 can be divided into 10 and 6. 20+10=30

4+6=10

30+10=40 T: Yes, we can divided the numbers into 2 parts, ones and tens. We can put the ones together, the tens together.

T：Actually, we can make a vertical to solve the problem.

T: We can write 4 in the ones column, 2 in the tens column. Here 4 means 4 ones. 2 means 2 tens. (teach 16 in the same way) T: 4 ones and 6 ones make 10 ones.

Then we write ‘0’ in the ones column and a small ‘1’ in the tens column.

The small one in the tens 实际操作中的调整

1. The students can understand the methods of carry addition. 2. The students can do the carry mental addition correctly.

PPT, worksheet

column means 1 ten. T: Finally we add all the numbers in the tens column: 2+1+1=4.

Here the number ‘4’ means 4 tens. So the answer is 40. T: 42 is greater than 40. So all the students can get on the bus. T: Everyone gets on the bus. Now we arrive in the zoo. First, let’s play a guessing game.

T: Yes. There are so many animals in the zoo. Look at this picture. What can you know? S: There are …

T: My question is how many monkeys and lions are there in total? Who can tell me the number sentence? (The teacher write the number sentences and ask) T: How to get the answer? S: We can make a vertical. T: T: We can write 8 in the ones column, 4 in the tens column. Here 8 means 8 ones. 4 means 4 tens. (teach 16 in the same way) T:8 ones and 6 ones make 14 ones. Then we write ‘4’ in the ones column and a small ‘1’ in the tens column. The small one in the tens column means 1 ten. T: Finally we add all the numbers in the tens column: 4+1+1=6. Here the number ‘6’ means 6 tens. So the answer is 64. T: Can you ask a question? S: …

T: The monkeys want to eat some bananas. Here are some bananas. Can every monkey get 1 banana? (make a vertical, teach in the same way) Step 3 Exercise. 1.

T: Now let’s play a game: There is a teddy bear in the top. If you can tell me the right answer, you can go up.

2.

There are 36 animals in front of me. There are 18 animals behind me. How many animals altogether? Step 4 Homework.

教学反思与教学改进