1. Understand and master the vertical method for calculating the addition of two digits.

2. Can correctly grasp the format and method of vertical calculation.

3. Cultivate students' ability of observation and analysis.

Teaching focus:

Be able to master the method of vertical calculation and calculate carry addition correctly.

Teaching preparation:

Positioning board, two-color film, computer courseware

Teaching process:

First, the initial perception

1. Provide students with a numerical board, and let them put out the required numbers with two-color films, 5, 10, 13.

2. According to the formula provided by the teacher, please put the two-color film on the numerical table twice: 5+8.

3. Ask students to compare two different arrangements, and tell which one looks more intuitive and why.

Summary: Generally speaking, on the bit value table, if a bit is full of ten, it will enter one into ten.

4. Ask the students to continue playing.

6+ 10 15+7

Second, the algorithm exploration

1. Show me 38+25=? Tell me about your calculation method.

(Name, teacher writing on the blackboard)

30+20=5038+20=5830+25=5538+2=405+25=308+5= 1358+5=638+55=6340+23=6333+30=6350+ 13=63

2. Expose the topic: These are all the algorithms we have learned before. Today we are going to learn another calculation method.

3. Media presentation.

Look carefully, what just happened?

(The key point is that a place's' 1 0 blue dichroic film became a1red dichroic film after it entered the tenth place. )

5. The process of vertical calculation can be expressed vertically, which is the new knowledge we are going to learn today: pen addition. Synchronize the position of the numerical board on the blackboard and write down the vertical calculation process on the blackboard.

6. Teaching vertical style

(1) What do you think should be paid attention to in vertical calculation?

(Group discussion, feedback)

⑵ Summary: We can sum it up in three simple sentences: "The digits are aligned, starting from the unit, from 10 to 1."

(3) Why did 10 in one place become 1 in ten places? (10 one is 1 10. )

Third, vertical exercises.

1. Huanhuan gave you several questions. Please use the method you learned today to calculate them. (Exercise 2) Question 1 Complete collectively. Questions 2, 3 and 4 are completed by students independently and corrected in groups.

2. Exercise 3: Don't count. Mark the questions you think you need to carry.

3. Media demonstration, asking students to find out the wrong ones.

(1) forgot to bring it.

(2) It should not be mentioned indiscriminately.

(3) The rounding number squeezes the original result from the tenth to the hundredth.

(4) The calculation result of one digit is 10, and zero is omitted after rounding, resulting in an accident that the result becomes one digit.

4. Ask students to randomly select two questions on the grid paper and use vertical calculation, and check them in groups. (Exercise 5)

Four. abstract

1. What did you gain today?

2. Is there anything you want to remind your child?