Addition and subtraction is a book published by Shandong Fine Arts Publishing House in 2009. This book is a baby's toy learning treasure. The main content is the calculation formula of addition and subtraction. Through interesting magic card games, the baby can learn while playing. So how to teach children to add and subtract within twenty?

Ten-point method

Decimal method is the most basic method of carry addition. It is not only suitable for addition and subtraction within 20, but also suitable for addition and subtraction outside 20.

Clever calculation of "+9"

When a child comes across a formula with the number "+9", parents can let the child try to calculate it in other ways, such as "+9" is "+10- 1", which will make the formula simple.

reciprocal

Many children who are new to mathematical addition and subtraction often use the "reciprocal method" when learning addition and subtraction within 20 minutes. But this method is more suitable for adding small numbers, such as "+1" or "+2".

Familiar numerical relationship

When children learn addition and subtraction within 20 minutes, parents can also train their children to be familiar with "multiples", because the multiple relationship in numbers is a special existence, and it is easier for children to remember when remembering.