Counting is the learning content of small classes, and our teacher thinks that every child should be able to count. However, we ignore that many children only start counting from "1". If you ask him to count from a number in the middle, they may not know how to count. Or children don't know how to get from 9- 10, 19-20, 29-.

Step 2: Let children master the relationship between numbers: for example, what is in front of 5? What's behind? 8 What's ahead? What's behind? Count forward from 5, count backward, count forward from 1 1, count backward.

The third step is to let children master the relationship between numbers: for example, which is bigger, 7 or 8? 12 or 4, which is bigger?

The fourth step is to let the children learn to read the questions. Many children can read the questions, but they can't understand them. Children know how to write "+"and "-",but they don't know how to read them. Let the children read them out, so that when they calculate in the next step, they can be told that when they read "add", they count backwards. When they read "minus", they count forward.

The fifth step is to teach children to know the unit and ten, so that children can skillfully say what the unit and ten in two digits are.

For example: 15, the unit is 5, and the decimal number is 1.

The sixth step is to teach children to calculate:

1, plus or minus hand index:

Addition, for example: 15+2= We tell children to keep the big number 15 in their hearts, and use their fingers to represent the small number 2 (let the children put their fingers out), with a "+"sign in the middle, that is, count their fingers from the number after 15, followed by1.

Subtraction, such as: 15-2= We tell our children: trust the big number 15, use your fingers to represent the small number 2 (let the children put their fingers out), and there is a "-"sign in the middle, which means counting backwards from the previous number 15, and the previous number 14.

Addition, for example: 15+2= We tell children that the sum of one digit and one digit is 5+2=7, and the sum of ten digits and ten digits is 1, so 15+2= 17.

Subtraction, such as: 15-2=, we tell children that the subtraction between one bit and one bit is 5-2=3, and the subtraction between ten bits and ten bits.

1-0= 1, then 15-2= 13.

Relatively speaking, "counting fingers" only applies to the addition formula in which one of the two numbers is singular, because if both numbers are even, then there are not enough fingers; Although "addition and subtraction of numbers" is difficult to learn, it can be applied to all formulas. From the perspective of sustainable development, I suggest "addition and subtraction of numbers"

Extended data

Addition (usually indicated by the plus sign "+") is one of the four basic arithmetic operations, and the others are subtraction, multiplication and division. For example, there are three apples and two apples, and there are five apples in total. This observation is equivalent to the mathematical expression "3+2 = 5", that is, "3 plus 2 equals 5". 3+2 = 5 and Apple are popular choices in textbooks.

In addition to calculating fruits, you can also calculate other physical objects. Using system generalization, addition can also be defined on more abstract quantities, such as integers, rational numbers, real numbers and complex numbers, and other abstract objects, such as vectors and matrices.

In arithmetic, the addition rules involving fractions and negative numbers are designed.

Addition has several important properties. It is interchangeable, which means that the order is not important, it is interrelated, which means that when more than two numbers are added, the order in which the addition is performed is not important. Repeatedly adding 1 is the same as counting; Adding 0 will not change the result. Addition also follows related operations such as subtraction and multiplication.

Addition is one of the simplest digital tasks. The most basic addition: 1+ 1 five-month-old babies and even other animal species can be counted. In primary education, students are taught to calculate the superposition of decimal numbers, starting with one digit, and gradually solving the more difficult number calculation.

References:

Baidu encyclopedia supplement