I. Origin of the activity

At regionals, the children found that the desk mat in the class was torn and was being glued with tape. Meng Xiangyi said, "This table mat has been glued several times. Can you exchange it for a new one? " So, we found Mr. Liu, the logistics teacher. He asked, "How long are the desks in your class?" How appropriate is the table mat cutting? "I didn't use a ruler directly, but guided the children to discuss how to tell Teacher Liu the length of the table mat after returning to work. Combined with the Outline Rules, teachers should use and create various conditions to encourage children to discover and compare the similarities and differences and changes of objects through measurement, and guide them to learn natural measurement. As a result, a series of natural investigation and education activities have been carried out, and How Long is the Table is one of them.

Second, the activity objectives

(1) Learn the correct measurement method, and initially find the relationship between measuring tools and measurement results.

(2) Guide children to fully experience the sense of success brought by measurement activities.

Third, activity preparation

(1) knowledge and experience preparation: put all kinds of measuring materials in the activity area one week in advance, and children have preliminary experience in measuring and recording.

(2) Preparation of materials: building blocks, paper clips, math sticks, paper strips and other natural measuring objects; Recording paper and pen.

Fourth, important and difficult points

(1) activity focus: master the correct measurement method initially.

(2) Activity difficulty: Find the relationship between measuring tools and measuring results.

Verb (abbreviation of verb) activity process

(A) Start: looking for measuring tools to stimulate children's interest.

1. Key questions:

Our class needs a new desk mat. How can I know the length of the table? (measurement)

(2) What can be used to measure the length of the table?

2. Show and introduce the measurement record, let the children discuss the tools to be used in each group in groups, and then go to the activity area to find and collect the measurement tools.

(2) Basic part: Measure the length of the table with different measuring tools and exchange the measurement results.

1. Choose measuring tools and explore freely.

(1) Take the group as the unit, select the planned tools for measurement, and record the results.

(2) Children exchange measurement results and guide them to look for the same measurement tools again.

Key questions:

Are we using the same table? The tables are all the same. Why do we get different results? (using different tools)

(2) What method do you use to prove that your measurement result is correct? How to make our measurement results consistent?

2. Standardize measuring tools and learn correct measuring methods.

(1) Question: Why is the measurement result of the same tool different?

(2) Play the video and let the children compare the measurement methods of three people. Which one is correct? Why?

(3) The teacher helps the children to sort out their experiences: when measuring, they should find the right starting point, aim at the edge of the table, and don't deviate from the edge, end to end. The measurement results record the number of measurements made by the measuring tool.

3. Choose measuring tools with different lengths to measure again, and record them to find the relationship between measuring tools and strategic results.

(1) Key issues:

What is the difference between the measurement results of the three measuring tools? (Numbers are getting bigger and bigger) What's the difference between three measuring tools: long building blocks, watercolor pens and wooden sticks? What secrets did you find from the measuring tools and results?

(2) Summary: The longer the measuring tool, the less the number of measurements, and the shorter the measuring tool, the more the number of measurements.

(3) End part: Let the children send the measurement results, and the activity will naturally end.

Let's tell Miss Liu the measurement results together and let her choose the results of a measuring tool to help us cut the table mat.

Sixth, reflection activities.

In the early stage of this math activity, put the corresponding game materials into the regional game, and encourage children to measure the objects they are interested in and record them.

The goal of the activity is to let children master the correct measurement methods and find the relationship between the measurement tools and the measurement results. Measurement activities are carried out in groups from beginning to end, giving children enough opportunities to communicate with their peers, try and solve problems. Let the children discuss what can be measured at the beginning, and then draw it on the record table, which embodies the characteristics of planning and cooperative learning of large class children. In the process of measurement, children can measure according to the planned tools and record the measurement results in their favorite way.

The focus of the activity is to let children learn the correct measurement method. I let the children try it themselves, observe and compare the measurement results, and find different measurement methods. Then through the video, let the children compare and find the correct measurement method. Especially after giving children a unified measurement tool-watercolor pen, children will re-measure with the measurement methods they have mastered, which highlights the key points. The difficulty lies in finding the relationship between the measuring tool and the measurement result, that is, the longer the measuring tool, the less the number of measurements, and the shorter the measuring tool, the more the number of measurements. Only long building blocks, watercolor pens and wooden sticks are used as materials. Through repeated operations and exercises, children find their own rules by comparing the measurement results first and then the length of the measuring tools, and find that the numbers are getting bigger and bigger.

Activity evaluation

The mathematical activity "How long is the table" comes from teachers' sensitivity to education and mature educational wit. When the children's needs in regional games were discovered, they communicated with the logistics teacher in advance because of the goal consciousness of mathematics education, which naturally contributed to this measurement activity.

The focus of mathematics education is the cultivation of mathematical ability. Specifically reflected in:

1. This math activity broke through the traditional teaching mode, and the children found their own measuring objects to measure at will; Video comparison, looking for the correct measurement method; Unified measurement object for measurement; Compare the measurement results of measured objects with different lengths. It fully embodies the process of mobilizing children's existing experience and actively constructing new knowledge.

2. Through the early observation in regional games, teachers can grasp the problems that children are prone to have inaccurate starting point of measurement and the objects to be measured cannot be connected, design and record three different measurement videos in advance, guide children to compare, find problems intuitively, and help children summarize and sort out the correct measurement methods.

3. In the activity, teachers encourage children to fully perceive and observe, and ask effective questions step by step, such as: What are the differences between the measurement results of the three measuring tools? (Numbers are getting bigger and bigger) What's the difference between three measuring tools: long building blocks, watercolor pens and wooden sticks? What secrets did you find from the measuring tools and results? Guide children to clear their minds in the discussion and reach an understanding, thus breaking through the difficulties of activities.