Process and method: guide students to experience a typical scientific inquiry process; Be able to ask questions and design schemes through thinking.

Knowledge and skills: be able to compare the quantity of solutions in various ways and make it clear that the same standards must be used. Know and learn to use measuring cylinder.

Emotional attitude and values: attach importance to facts, dare to put forward different opinions, be willing to cooperate and communicate, and cultivate self-confidence and rigorous scientific attitude.

Teaching focus:

Guide students to experience the typical scientific inquiry process.

Teaching difficulties:

When exploring, you can ask questions and design experimental schemes.

Preparation materials: one set of four bottles with different sizes in each group, sink, funnel, disposable cups, jar, measuring cylinder, balance and observation record sheet.

Teaching process:

First, create a situation and put forward a guess.

1. Show the courseware. Teacher: In this class today, the teacher brought two old friends to everyone. Who are they? What happened to them? Oh, there is something wrong with Bajie. Can the students help him?

Which bottle of water do you think is more? Can you tell me your thoughts?

Second, compare the water quantity of different containers in various ways.

1, Teacher: Sometimes you can't get an accurate answer just by looking at it with your eyes. Then what should you do?

2. Group discussion: What method can you use to compare the water quantity? Let's discuss it in the group. Let's compare which group has come up with more methods and better methods.

3. Reporting and communication: different methods of comparing water quantity. Introduce the use of measuring cylinder in time and know the measuring unit of milliliter.

4. Which group do you think has the best design? Which group uses the simplest equipment? Which group has the least experimental steps? In order to encourage students to continue to look for new methods.

Third, experimental exploration.

1, using the equipment provided by the teacher, discuss in groups which method you plan to compare and what equipment you need, and then the group leader will come up and get the equipment you need.

2. Students experiment and record the results. Teachers patrol and do a good job in the safety guidance of experiments.

3. Report and exchange experimental results.

Fourth, try to estimate the amount of water

1, Teacher: Just now, students learned which bottle contains the most water through experiments. Do you want to do further research now? How do you want to explore?

2. Students experiment and make records.

3. Report the experimental results.

Verb (abbreviation of verb) summary.

1. What did you get from this lesson?

In fact, science is around us. As long as we observe carefully and think more, we can find out from real life, and then solve problems in our own way or explore with friends, and you will find the mystery of science.

Sixth, extracurricular extension.

Make a bucket that can hold 500 ml of water with the materials around you (such as beverage bottles); A bucket that can hold 400 ml of water. How can these two barrels hold 300 ml of water?

Reflections on the teaching of water quantity comparison

This lesson has also been greatly improved compared with the previous "Comparative Water Quantity". It should be said that it is more scientific than before, and the taste of inquiry is stronger. From guessing the number of three bottles of water, to discussing the comparison method, to making your own measuring cup for measurement, and finally understanding the measuring cylinder measurement. Compared with before, there is one more step to make the calibration cup, which weakens the step of estimating the liquid volume. Although this activity is very attractive to students, it is also very interesting. However, estimating the volume of liquid is also very important for students. Besides, combined with teaching practice, I think it is very difficult to fully develop these links in a 40-minute class. If we can start with enough time, that's a good thing and what I expect.

In the actual teaching, I started the previous activities according to the arrangement of the old textbook. This activity is very attractive and interesting to students. Encourage students to compare water quantity by various methods and make a comparative analysis of these methods, so that students can understand that some methods are simple and effective. For the latter two activities: making measuring cups and knowing measuring cylinders, I feel very nervous because of the class time. I think it is very difficult to fully develop these links in a 40-minute class. So I still omitted the step of drawing a calibration cup to measure myself. In fact, after removing this link, the class time is still very tight. For children in grade three, it takes a lot of time to know the novelty of measuring cylinder, and even more time to actually measure it. I also made a full design in estimating the liquid volume, and spent a few minutes helping my classmates to estimate the liquid volume. I think it is helpful for children to establish the volume of milliliter units. I think it's also good to put "doing calibration cup measurement by yourself" in extracurricular group activities.