The plus sign is pointed and the minus sign is round. The addition should be large and the subtraction should be small. Look at the problem before you do it. I know whether it can be calculated. If you add up, put these two figures together. If you do subtraction, separate the two numbers. Finally, do a calculation to see if it is correct.

Vertical addition and subtraction refers to vertical addition and vertical subtraction, as follows: vertical addition: the same number of digits are aligned, and if the sum exceeds 10, it goes forward 1. Vertical subtraction: the same number alignment. If it is not enough, borrow 1 from the last digit as 10.

Knowledge expansion:

Kindergarten is the first step for children to leave family life and enter school education. Kindergarten not only provides a safe and healthy living environment for children, but also helps children develop their physical, cognitive, emotional and social abilities through education.

The educational concept of kindergarten is to help children play middle school through various games and activities, and to improve their interest and ability in learning. Kindergarten teachers will formulate different teaching plans and courses according to children's age characteristics and needs, including music, art, sports, Chinese, mathematics, science and so on.

In kindergarten, children will encounter all kinds of toys and games, such as building blocks, puzzles, paintings, musical toys, sports equipment and so on. These toys and games can help children develop their imagination, creativity and hand-eye coordination.

Kindergarten teachers have received professional training. They not only know how to take care of their children's physical and mental health, but also know how to communicate and interact with them. Teachers will pay attention to each child's personality and needs and give them special attention and guidance.

In kindergarten, children will also meet peers from different family backgrounds. This kind of multicultural communication can help children broaden their horizons, understand different cultures and values, and cultivate their intercultural communication skills.

Kindergarten is an important stage of children's growth and development. Here, children can get comprehensive education and care, develop their physical, cognitive, emotional and social abilities, and lay a solid foundation for their future study and life.