Teaching objectives:

1, guide students to learn to solve the problem of "finding a number more than or less than a number", and understand and summarize the methods to solve "finding a number more than or less than a number".

2. Feel the process and method of "finding a number more than or less than a number" in the process of observation and operation, so that students can use the knowledge of subtraction within 100 to solve some simple problems in life.

3. Cultivate students' awareness of the application of mathematics life and their ability to solve problems.

Learning task: Understand and summarize the solution to "finding a number more than or less than a number"

Teaching process:

First, passion guidance:

1. Sing the children's song "Left Hand and Right Hand". After singing, the teacher demonstrated and said, "Hold out your right hand, your left hand and your fingers. You found a good friend. For example, how many fingers are there in the right hand than in the left hand? "

Lead out: as much.

2. Fill in the blanks:

There are 10 five-pointed stars. There should be () circles as many as five-pointed stars.

There are four teacups, as many as teacups, and there are () teacups.

Just now, we have solved the same number of problems. In this lesson, we will solve the problem of "seeking greater than or less than a number". I believe that students will be able to successfully complete their learning tasks!

Second, people-oriented learning:

1. Task demonstration:

Example 4( 1) Situation Map

Teacher: This week, our school conducted a big campus hygiene appraisal. You see, the school health appraisal form has been posted. Please observe carefully and read the question:

(1) What do we know? What is the problem to be solved?

(2) Try to solve the problem by drawing and communicating in the group.

2, autonomous learning:

(1) Students carefully observe the reading questions and get mathematical information.

(2) Try to solve the problem by drawing and communicating in the group.

3. Display communication

(1) Student 1: I know that Class One got the red flag of 12, and Class Two got three more. How much did Class Two get?

Ask two children in the group to go to the blackboard. The first one shows the small red flag of 1 class, and the second one shows three more small red flags than 1 class.

Health 2: To find the number of faces in Class Two is to find the number of three ratios 12. By addition, the formula is 12+3. (blackboard writing)

(2) Example 4(2),

Students look at the problem: the small red flag in class three is 4 less than that in class one. How many faces are there in Class Three?

Group cooperation can be solved by using the information in drawing, painting, posing or children's demonstration.

Students talk and say why. How many noodles did Class Three get? That is, what is 12 times 4 less than? )

(3) Find the rules and methods.

Find a number greater than a number, and use () to calculate;

Find a number less than a number and calculate it with ().

Third, the target detection:

1, finish "doing".

What information did you get from the picture? Who are the requested eggs and goose eggs related to?

2. Students solve problems by themselves and report their ideas.

3. What other similar questions do you encounter in your life that can be answered with mathematical knowledge?

What have we learned from today's study?