In the first week, we are still finishing the main textbook of the story "The Kingdom of Blue Flowers". In the main textbook, we wrote: "Anger makes people lose strength. If a person only thinks about the starry sky, there will be no darkness in his mind. " So we painted the starry sky together in class.
We wrote again—
When you face the vast starry sky or the flowers all over the mountains, you can't help but marvel at this huge number. So we began to count the corn kernels on a corn cob. First, let the children guess how many corn kernels (magic seeds) there are on a corn cob. At first, several children guessed conservatively, 35. Sixty? Basically, they are all below 100, indicating that they don't have much experience in large numbers. Two boys blurted out: "One trillion!" Or "infinite!"
I asked two people to count a corn cob in pairs. In some groups, two people each count a pile, and in some groups, one person breaks corn kernels and the other person counts; Slowly, more and more groups divided the corn kernels into five piles, 10 pile, or even 100 pile ... Rabbit and Hui originally counted each other, and soon gave me a number. I asked with bare corn stalks, "Are you sure?" They looked at each other: "I don't know if I added it correctly." I encourage them to walk around the classroom and see if the children in other groups count. They turned around, then returned to their positions, divided a can of corn kernels into a pile 10 10, and counted them again. Super learning ability!
Very interesting. In Yan and Yu's group, there are two little girls who are very focused on sorting corn kernels, one with five small flowers in a row and two small flowers in a row. Rain said happily, "Let's take a big walk together until we reach the end of this row of tables." Without saying a word, I probably think there are too many corn kernels to put two numbers together, so I still insist on a pile of five. So they all counted their numbers.
After these attempts, let's compare how to calculate large numbers more conveniently. Naturally, I asked the children to put the corn kernels into the small bag (10), and then put the small bag of 10 into the big bag. From this, the study of "One, Ten and Hundred" is gradually introduced.
At this time, it coincides with the winter solstice festival. Let's review 99 songs and talk about the ancient custom of counting 99. In the eyes of the ancients, "nine" was the greatest positive number. When counting the days, count 19, and then count 29, so 998 1 day passes, winter goes and spring comes, and cows are everywhere. Last year, the whole class ordered plum blossoms on the cold map. This year, we used copper coins to record the weather (rain, snow and wind) on the 99 cold map, hoping to make some preparations for measuring the study time of grade three.
In order to make it convenient for children to count nine, I also drew a monthly calendar on the blackboard, so that children can clearly count the days after winter. At the same time, the seven-day cycle is also paving the way for the multiplication table of seven.
-
In the second week, I began to show coins to my children. I started from "Yuan Jia" and made a Christmas market for two days, so that the children could experience the work of stall owners (counting money, keeping change, keeping accounts), customers and banks (changing change) in groups. It is fun to simulate the Christmas market. When I asked the children to play stall owners and customers in groups and buy dates, building blocks, corn seeds and precious stones with teaching money, some stall owners thought it was too much trouble to change them. They were looking for 3 yuan, so they generously used 5 yuan. Some stall owners are very dissatisfied with the customer 50 yuan buying a building block and changing all the change on the booth; Some customers calculate the total price of goods very carefully, and they have to go to the "bank" to exchange change before buying; There are also some customers who bought it at buy buy willy-nilly, and their hands are full of dates. Finally, I had to "help" and share it with the hard-working stall owners.
In the grouping activities of the simulated market, three people are responsible for a booth, which is responsible for counting money (Mr. Jia and Mr. Cheng), changing money (Mr. Minus), changing money (Mr. Split Numbers) and keeping accounts respectively. The child found that the demand for change was particularly great, and the child was asked to manage the bank to exchange money the next day. The hardest part of the whole activity is bookkeeping. In the end, when the stall owners count money, they are all confused accounts, and the children have more money on hand after buying things.
In practice, children are familiar with different coin combinations. For example, how to use 100 yuan, 10 yuan, 1 yuan to get "138 yuan"? What if you add money from 20 yuan and 5 yuan? Through various splits, I am further familiar with the concept of "one hundred" corresponding to three digits. Also in the process of market transactions, the rabbit sighed with emotion: "One hundred dollars is useless, one yuan is the best, and it is convenient to buy anything."
On the weekend, children were assigned an assignment to take 10 yuan to go shopping (it needs more than three yuan) to record the quantity and price of the things they bought and the money they finally got back. This homework is generally done well, and children can plan their own money reasonably. Ten dollars can buy more things than I expected, ranging from batteries to soy sauce, and children who are obsessed with weighing a few sweets and a garlic. Come to this shopping experience more often, and I believe that no one will spend a lot of money when they go to the market next time.
-
The third week coincides with the New Year. I prepared some coins for the children as "lucky money". Each of them has 10 dimes, two dimes and one yuan. There are not enough cents, so we have to pass them around. We know different monetary units by rubbing coins. At the beginning, when it comes to the conversion of yuan and jiao fen, there are indeed children who have no concept at all-they can't see a penny in life and can't buy anything for a few cents. What's the point of saying that one yuan is 100?
Here is an interesting "cognitive conflict": I asked the children to count the coins in the change jar. Some children naturally start rounding up, such as changing 10 1 cent, two 50 cents into one dollar, 10 1 cent into a dime, and so on. But in some groups, the reported amount of money is similar to "7 yuan 50 18". Obviously, they counted dimes and cents respectively, but they didn't know the conversion between dimes and dimes. Even though we have studied "1 yuan = 10, 1 = 10" before, such knowledge lacks the connection with life experience. When children count a penny as 18, what's wrong with saying "50 points in 7 yuan is 18"?
So the next day, I asked my children to compare the score of 7 yuan 18 and 7 yuan 4 1, which is bigger? When the proportion is small, we need to turn the expression of money into a unique expression. We also learned the symbolic representations of "greater than sign" and "less than sign" by the way.
Later, I asked the children to combine different "one yuan" with coins in their hands. Imagine you go to the store to buy something for one yuan. How many different possibilities are there when paying? At the beginning, some children said two or three kinds, and the most said four kinds. I drew the combination of "one yuan" they thought of on the blackboard, such as:
1 yuan per block
Two fifties.
10 dime
1 50 yuan and? Five dimes
These things may happen in life. When one child said, "100 pieces 1 cent", another child said, "two nickels and nine dimes" ... The children inspired each other and I wrote all over the blackboard!
Of course, we will also discuss why no one takes 100 1 cent to buy something with one yuan, because it is too much trouble to count! Some children also said that they couldn't find that many 1 points, and now they don't send them. Therefore, a larger quantity unit has become a real and reasonable demand.
Parents can usually take their children to the vegetable market, let them help calculate the money, move things and come back to cook together. This is a beautiful life lesson. Don't give all the lucky money for the New Year to large bills, whether you can spend it or not. Give the children some change of five dollars and ten dollars. They can also buy some new year gifts for their families, even a Chinese cabbage in the New Year's Eve dinner, to encourage their children to contribute to their families.
The first task in the new year is to help wash dishes at home. I recorded how many dishes and bowls I washed this day and wrote them on a small note to the secret teacher. At the beginning of this homework, we recite the children's song "The bench is crooked" in the morning. When the last sentence reads "seven dishes and eight bowls", children will either sit or lie down and express their dishes or bowls with their body posture. Everyone counts how many plates and bowls there are. After playing this game for a while, I wanted to take the opportunity to encourage children to do some housework and cultivate a sense of order in housework, so after the homework of "spending money on shopping", there was the homework of "housework".
Real life is always more colorful than the conceptual world. Besides vegetables, there are pots, knives and forks, chopsticks and so on. The notes handed in by the children are all pictures, which are dazzling. So I gave you a "puzzle" with a small note. For example, she painted and washed six dishes, and she washed three more bowls than plates. How many bowls did she wash? Children are very interested in practical problems in life. On the note handed in the next day, Jun Jun directly gave a question: "I washed an extra bowl, and there were more plates than chopsticks 1. I washed nine samples in a * * *. How many chopsticks, how many plates and how many bowls? " Isn't it interesting?
In the fourth week, we rehearsed St. Martin's plays in the morning circle and reviewed the multiplication table of 1-5 constructed this semester. Through the combination of VI=5+ 1, we derive the multiplication table of 6. We use a set of dimes and dimes to count money, so that children will naturally think that the multiplication table of 10 and 6 contains the multiplication table of 5.
To sum up, this semester, in the study of multiplication table, we deliberately slowed down the pace. On the one hand, it takes time for children to practice counting in the morning circle and let the rhythm enter the body. They are not familiar with the multiplication tables they have made. On the other hand, I intentionally broke up the study of multiplication table, and didn't want to make the math class too structured and repetitive, so I introduced more games to cultivate my sense of logarithm and number. On this basis, the multiplication table of 7- 12 will be completed next semester to further consolidate the addition and subtraction within 100.