Teaching objectives:

1, combined with the specific situation, on the basis of a preliminary understanding of some objects, understand several parts. Compare the sizes of two fractions with the same denominator.

2. Cultivate hands-on operation, cooperation, communication and expression skills.

3. Experience the connection between scores and real life, actively participate in specific mathematics activities, and have a sense of intimacy with mathematics.

Teaching emphasis: molding takes several minutes.

Teaching difficulty: compare scores with the same denominator.

Teaching preparation: papers, courseware, teaching AIDS for circular demonstration.

First of all, an exciting introduction.

Students, look who's here, xx. The elf has come to learn from you. Last class, we learned a quarter. How to express a quarter of a circle? Say its name. Student: Divide the circle into four parts, each part is a quarter of it. Take out a circle evenly divided into four parts, pick up the middle piece and say that the part of 1 is a quarter of this circle. Teacher: divide an object or figure into several parts, one of which is its score. Let's get to know a few points in this class. Write on the blackboard.

Secondly, explore several points.

1, let's start with this square paper in hand. Group cooperation requirements: divide the square into four parts on average, then paint it as much as you want. After painting, show the painted part with scores. Finally, tell the group what they think. Students speak completely, and the teacher writes down the corresponding scores on the blackboard.

Teacher: Can you find out how they are expressed? What do they have to do with 25 cents?

2, students can think of several meanings of a quarter from a quarter, which is really strong in reasoning and good at observation and thinking. Now, please take out the prepared ruler, draw a line segment with the length of 1 decimeter on the notebook, and divide the line segment into 10 parts on the scale. Finish painting. The teacher asked: Can you tell me how much each book costs? Q: How many copies are three, four, six and seven? There are a few tenths of these scores. In a word, a few tenths is a few tenths.

Numbers are like ... all fractions. Can you name a score based on appearance? The students said, write on the blackboard.

4. How many parts does the observation score consist of? The teacher chooses a score and names the parts on the blackboard. Name the other scores.

With so many scores, can you choose an example to explain how it is expressed? How to write? For example, if a number is divided into four parts on average, the denominator will be written as four parts. If you take 1 part, the numerator will be 1.

6. Now do you understand how several parts came from? Can you say it in one sentence?

7. Compare the numbers and scores of Example 6, and compare the sizes. One group has a picture, and the other group has no picture. Let the students find a way to compare. See what you find.

Third, consolidate the practice.

Can you show the colored parts in the picture below with scores?