1 and the first group of addition and subtraction of Xue 8 can be described according to different pictures, and the corresponding formulas are listed, so as to perceive the quantitative relationship expressed by the addition and subtraction formulas.
2. Learn the exchange law and use it to find another formula.
3. Actively explore mathematical activities and be willing to talk about the exploration process.
Activities to be prepared
1, teaching AIDS: formula cards within 7, four castle maps, four paintings and four long cards.
2, homework, pens, small stickers.
Activity process
First, review the composition of 8 and the formula in 7.
1, the teacher and the children play eight "ball games" together.
2. Review the formula within 7 in the form of "driving a train".
The teacher showed the formula and the young man drove the train to answer.
Summary: Today's train runs steadily and quickly, which is really good! Where did the train go?
Second, situational awareness-picture learning The first group of addition and subtraction 8.
Teacher: You see, the train took us to the family kingdom. There is a 1.2.3.4 house. Do you want to visit such a beautiful house? The owner of the house said that there was a picture in each of the four houses. Please ask our children to tell the things in the picture in three sentences by asking questions. If anyone can say this correctly, they can enter the house smoothly. Do you want to talk about it? Ok, let's start the discussion.
1, children's first exploration operation-telling with pictures
(1) Teacher: Please tell me which house did you choose? What does it say? There is a bird in the tree, and seven birds are flying. How many birds are there in the tree? ) Collective verification, talk to the collective.
(2) Please tell the children in other housing estates separately (after verification by everyone, tell them collectively).
Summary: Ah, our children are really capable, and they can make things clear in four families at once. The owner of the house also praised us as the smartest little guests.
2, children's second exploration operation-list the formula while talking.
Teacher: The owner of the house has spoken again. He wants to test our children. Just now (www.birthhealth.com from Reproductive Health Network) asked the children to talk about things in four houses. Now let the children write down a formula problem according to what they just said.
Explain the operating requirements of children.
Teacher: How did you record it? Why use the addition formula? Ask a child to come up and remember this addition formula while telling the teacher. (1+7=8) Read the formula twice together. By analogy, three other formulas are obtained respectively. 7+ 1=8、8- 1=7、8-7= 1。 Read the formula again.
Third, experience understanding-exchange rule.
1, learn the exchange law of mathematics.
Teacher: The teacher takes the picture away and lets the children observe these formula problems. Do they have any little secrets? See who can discover the secret first.
Summary: 1+7=8 and 7+ 1=8 are the same, but the total number remains the same. So when you see 1+7=8, you will immediately think of 7+ 1 = 8. We call them good friends. See also 8- 1=7, and immediately think of 8-7 = 1. We also call them good friends.
2. Practice swapping.
Teacher: The teacher took out the question card and asked our children to tell who his good friend's question was at once. 1+7=8(7+ 1=8)、8- 1=7(8-7= 1)
Fourth, group operation.
Teacher: There are many math problems in Zhaiguo. The owner of the house said that if you do these math problems correctly, everyone will get a small sticker. Would you like to have a try?
1, the teacher introduced various questions.
(1) See the formula in the figure.
(2) the rule of experience exchange.
2. Summary of opinions.