1, initially perceive the addition and subtraction of three numbers, and can calculate the number with the help of physical objects or learning tools.

2. Be able to think positively and improve understanding and calculation ability.

3. I like to participate in mathematical calculation activities and experience the success and interest of the activities.

Activity preparation:

1, teaching aid preparation: draw a curved maze on the ground; A number of ant headdresses; 4~5 sugar cans with numbers written on them; There are many candy bean cards with numbers written on them; Wax gourd card and biscuit card (printed with numbers within 20); There are four baskets.

2. Preparation of learning tools: beads in Golden Beads; Nobody has 20 soybeans.

3. Operating Manual, Volume 6, Pages 43-44.

Activity flow:

1, preheating activity.

Teachers and children greet each other.

Online games: review counting. The child listened to the drums, and the sound became louder or smaller with the size of the drums.

2. Group activities.

Create a situation: ants move food. The ant family is really busy today. Look, they keep carrying food. Let's help them.

Review the addition and subtraction within 20.

Teacher: There is a lot of food hidden in the maze. Let's break into the maze first.

The game "Ants Walk the Maze". The children are divided into four groups, each with an ant headdress to play the role of small ants crawling on the ground. To get out of the maze, we must work out the formula to block the intersection and see which group of children get out of the maze first.

2 Learn 3 plus Teacher: Wow, a lot of food. Ants like jelly beans best. Let's move the jelly beans first.

The game "Ants Move Sugar Beans". There are 4-5 sugar cans marked with numbers in front of the teacher. Children play with ants and have to move three jelly beans at a time. Only when the sum of the three numbers on the three jelly beans is exactly the number on the sugar can ants put the jelly beans in the sugar can. Let the children think about it. Which three kinds of jelly beans can be grouped in the same sugar jar? You can use the learning tool "Golden Ball" to operate.

Teachers and children check whether the numbers on the three jelly beans in the jelly bean jar add up with the numbers marked on the outside of the jelly bean jar.

(3) The number of learning 3 decreases continuously.

Teacher: The ant family just moved out 20 jelly beans. Brother Mouse stole 5 and Brother Mouse stole 3. How many jelly beans are there in the ant family? Children think while operating, list formulas and calculate numbers. Teachers can provide children with 20 soybeans to operate, and the game can be repeated by changing numbers.

3. Game activities.

Teacher: There is still a lot of food. Come and move it outside.

(1) the game "ants carrying wax gourd". Children play ants, and their numbers are less than 20. When the teacher says a certain number, for example, the teacher says "17", three ants who add up the numbers to get 17 form a group, run to the blackboard, Kolor the wax gourd marked 17 and put it in the basket. The game continues.

② The game "Ants Carrying Biscuits". When the teacher says a certain number, if the teacher says "5" and the number of three ants is 5, then the ant with the largest number stands up first, and the other two ants once put their hands on the shoulder of the previous ant to form a team, run to the blackboard, take away the biscuit cards marked with the number 5 and put them in the basket. The game continues.

4. Group activities.

The first group: moving soybeans. Children use soybeans to calculate the increase or decrease within 20.

Group 2: move soybeans. Children use "golden beads" to calculate addition and subtraction within 20.

Group 3: Find a kite. Children help ants take food home. Other animals want children to help them find kites. Do the activity of "looking for kites" on page 43 of volume 6 of the operation manual. 5. Exchange summary and tidy up school tools.