Dear Judges: Hello everyone!I am the No. 1 candidate today, and the topic of my trial lecture today is "Understanding Millimeters and Decimeters", so I will start my trial lecture below.
1. Create scenarios and introduce new lessons.
Teacher: Hello classmates!You may be seated!
Teacher: Students, do you like to watch Journey to the West?
Teacher: Oh, everyone likes to watch it!So which of the four Tang Seng do you like the most?
Teacher: Some people like Zhu Bajie, and some people like Sun Wukong. Why do you like Monkey King?Because Sun Wukong will change seventy-two. Yes, Sun Wukong will conjure a lot of things as long as he swings his golden hoop stick, but it's amazing!Today, the teacher invited Sun Wukong's golden hoop stick, please look at the big screen!What happened to the golden hoop stick?
Teacher: Well, the golden hoop rod sometimes becomes longer and sometimes shorter. So how long is the golden hoop rod when it becomes so short?Do you know how to measure the length of a golden hoop rod?The teacher saw that everyone was lost in thought!We will know through today's Xi. Today we will learn the understanding of Xi millimeters and decimeters.
2. Teacher-student cooperation, new knowledge.
Teacher: First of all, please look at our math book, can you estimate how many centimeters the length, width, and thickness of the math book?Oh, there are already people who are eager to try, and the teacher sees that some people are comparing with their hands. How long do you think they are?Some students said that it was about 23 centimeters long, 16 centimeters wide, and 1 centimeter thick. Hmm, do you think he's right?So how do you verify that it's not correctly estimated?Yes, you have to measure honestly. Can you use a ruler to measure the length, width, and thickness of a math book?Now, let's take measurements in small groups of 4 of you!
Teacher: Oh, everyone has finished measuring, so let's ask the representatives of Group 3 to get up and speak!Teacher: Well, she said that the length is 26 centimeters, the width is a little more than 18 centimeters, and the thickness is less than 1 centimeter. Some of them are less than 1 cm in length, so what should I do?Is there a unit smaller than a centimeter?This classmate mentions millimeters. You know so much!Yes, it can be measured in millimeters when the length of an object is shorter than a centimeter or when it is required to be measured more accurately. It is represented by a letter as mm. Do you know how long 1 mm is?The teacher saw that everyone was lost in thought!Please look up and look at the ruler in the courseware, each small grid in the middle of 1 cm represents 1 mm. Let's count how many 1 millimeters are in the middle of 1 centimeterIt's so fast!Someone rushed to reply that there were 10, and yes, 1 cm = 10 mm. Okay, we know how long 1 millimeter is, so will you compare them with gestures?Please reach out and compare the length of 1 mm to 1 mm. Some students found that 1 mm was too short, and it was not easy to compare. 1 millimeter is only a small block long, and we can compare the distance between the index finger and the thumb about 1 millimeter. After comparing the length of 1 mm, let's find out, which items in life are about 1 mm in length?Teacher: This student found a coin, well, he is really good at paying attention to life!
In addition to this, the thickness of our ID card is also about 1 mm. For a relatively short object like this, we can all use millimeters as a unit.
I just learned about the unit of length smaller than the centimeter, so is there a larger unit of length than the centimeter besides the meter?The student on the right is really knowledgeable!It is also known that the decimeter is also longer than the centimeter. So how long is 1 decimeter?Please look up at this meter ruler, a length of 10 centimeters like this is 1 decimeter. Teacher: Okay, can we summarize how much is 1 decimeter?Some people use one hand to compare, directly the distance between the index finger and the thumb is 10 centimeters to the ruler, which is 1 decimeter, everyone will use both their brains and hands!Teacher: For example, when we straighten the index finger and thumb naturally, the distance between them is called 1 decimeter, and the length of your 1 tree is about 1 decimeter.
Teacher: Let's find things in our lives that use decimeters as unitsThe next student found the length and width of the math book, and the length and width of the desk. These are the lengths of objects that are longer than centimeters, so we can use fractions when measuring the length of objects longer than centimeters.
Meters as units. Come to think of it, we also know that 1 meter is longer than 1 centimeter, and it is longer than 1 decimeter, so how many decimeters is 1 meter?to 10 decimeters. Really transfer knowledge!Indeed, 1 meter = 10 decimeters.
Let's fill in the information again: 2 centimeters = millimeters, 80 centimeters = decimeters to exchange your ideas with your tablemates.
He felt that 2 centimeters was equal to 20 millimeters and 80 centimeters was equal to 8 decimeters. Do you think he's right?Not bad!Let's summarize what is the relationship between the units of length of meters, decimeters, centimeters, and millimetersThat is, the advance rate between each two adjacent length units is 10.
3. Consolidate Xi.
Teacher: It seems that everyone has almost mastered it!The teacher also wants to test everyone's mastery!Complete the Xi questions at the end of the textbook and fill them in. Let's get started Teacher: Do you have the same answer?It seems that everyone's accuracy rate is very high!
Fourth, summarize and review.
Teacher: What have you gained from learning Xi this lesson?Please.
Let's talk about this girl with glasses. Teacher: She said that she learned that 1 decimeter = 10 centimeters, and 1 centimeter = 10 millimeters. Learned that the advance rate between each adjacent two lengths is 10.
Teacher: It seems that everyone has gained a lot from this class!That's all for today's lesson, please come down and complete the required questions after class, and students who have spare time to complete the optional questions, and find out which problems can be solved with the knowledge learned today in life. Students are out of class!
Conclusion: Dear teachers, the above is all the content of my trial lecture, can I erase the board book?