Task 1: How many beans are there on the plate?
Miss Gao: Each group will be assigned a plate with a handful of beans in it. How many beans are there on the plate? Try to count it.
? Some groups divide the beans on the plate into four hands, and each person counts the number of beans in his own hand. Four people add up to the sum of beans. Learn teamwork and be able to solve problems with the help of teamwork. Well done!
Miss Gao: Now, can you think of a way to show me how many beans there are? At this time, you can use the containers I provided, such as plates, boxes, disposable cups, etc.
? At this time, a keen little shell found that there seemed to be * * * similarities between the plates, boxes and cups I provided. There are ten "petals" outside the plate, ten small squares in the box and ten paper cups. I told him quietly that he had discovered a "big secret".
? Each group began to "eight immortals crossing the sea, each showing its magical powers": some groups chose to count beans with a palette, each "petal" contained 10 beans, and the rest were placed in the position of "stamens";
? Some groups choose to pack beans in small boxes, each box is 10, and the last six are also packed in small boxes;
? Some groups choose to put beans in disposable paper cups. After using ten paper cups, they put the remaining beans in the box.
? As soon as the above method came out, a small shell immediately asked a question: Why are there six beans in a small box? I don't think these six can be put in a small grid, it should be every10; In the third group of boxes, there are two in each small grid, and we can't see how many at a glance. Before we tied sticks, we all tied them together with sticks of 10 for clarity.
Miss Gao: Wow, all your questions are great. Then please count your beans again in the following way: each small box contains 10 beans, each disposable plastic cup contains 100 beans, and the rest are put in the palette.
? Small shells act quickly and immediately reload beans in a new way. Enjoy a new way to count beans.
Task 2: How many beans are there in your first group?
Miss Gao: As soon as the task is successfully completed, we will enter the second task. Please continue to use the above method and count how many beans there are in your group.
? Wow, after counting all the beans in the group, the small shell suddenly became excited. Teams began to set out and soon entered the state. They all chose to count beans in disposable plastic cups, because they said they brought a lot of beans, which must have exceeded 100, so they skipped the box and started counting beans directly with disposable plastic cups. The scene of counting beans is spectacular. Every little shell concentrates on counting beans. I quietly turned around and found many interesting ways: one group implemented the "four-person cooperation system", and each person counted 25 at a time, which was100; One group implemented the "dry contract system", each with two cups, and all the calculated 100 were put together. In one of the "contracted out" groups, I found that a small shell counted to 100, but it was counted by ten. After counting ten, I made a small mark on the paper, which made the counting fast and accurate.
? The process of counting beans is also full of joy. Look, they are "chasing" and "fleeing" beans.
? Counting, suddenly someone shouted: teacher, we don't have enough cups. We need new cups! I went to have a look, and sure enough, I used a disposable plastic cup of 10. There are already 65,438+000 beans in each plastic cup, and there is no place to count them.
Miss Gao: There are no new disposable plastic cups. There can only be ten in each group, no more. But now I can provide you with a new container, a big glass bottle. You can pour the beans in these ten cups into the glass bottle. Guess how many beans are in the glass bottle?
1000, 1000! ! ! I heard many voices shouting at the same time.
Soon, another group filled the second bottle.
? Slowly, the activity of counting beans came to an end, and the remaining beans were put into plastic cups, boxes and plates. The beans in each group have basically been put into the container as required. Let's take a look at the results of some groups!
What they told me was:
A bean on the plate represents a bead on a drill and a 1. The plate is full of 10, so it will be put in a small box.
A small square in the box represents a bead in the tenth position and a 10. 10 cube is full. If it doesn't fit, it should be poured into a disposable plastic cup.
A disposable plastic cup represents one hundred beads and one 100. 10 The plastic cup is full. If it doesn't fit, it should be poured into a large glass bottle.
A large glass bottle represents a bead in a thousand places and a 1000.
Miss Gao: 10 What if the big glass bottle is full? Don't worry, those beans are on the shelf now, quietly waiting for us to meet them again tomorrow.
It says on the back:
? The understanding of the number within 10000 is to further understand the number on the basis of learning the number within 100. It is also the basis for learning the calculation of numbers below 10,000, and for understanding numbers above 10,000 in the future. It is of great significance to develop students' sense of numbers and cultivate their awareness of estimation. This time, I hope that through the activity of counting beans, students can experience the development of numbers, know the counting unit "thousand", initially understand the actual meaning of numbers within a thousand, accurately say the numerical order of thousands, hundreds, tens and units, understand the composition of numbers within a thousand, and initially understand the decimal relationship between adjacent counting units, so that they can identify, read and write numbers within a thousand. Let students feel the meaning of large numbers in specific situations, cultivate students to look at things around them from a mathematical perspective, analyze the consciousness and ability of various phenomena in daily life with the concept of numbers, and promote the development of students' sense of numbers; Cultivate students' interest and self-confidence in learning mathematics and enhance their awareness of mutual exchange and cooperation.
? In addition, some big shells still remember the activity of producing bean sprouts last year. So this year, we continue. Let's turn beans into bean sprouts, beans into bean sprouts and beans into beans, shall we?