1, the addition formula without carry: (Be sure to see that Chu Jin Chu does not carry)

Fast addition technique

A: Two digits plus one digit: write down ten digits first, and then write down the sum of the digits.

B two digits plus two digits: write the sum of ten digits first, and then write the sum of one digit.

C multi-digit plus multi-digit: write the sum of the numbers on the same digit in turn from the high position?

2、? Carry addition formula (be sure to observe whether to carry)

Quick addition technique? The key of carry addition is to push 1 to a higher number of digits. Since it's a definite thing, can you push 1? After observation, you can start counting from the high position.

A two digits plus one digit: write the sum of ten digits plus 1 first, and then write the single digits of the sum of single digits (using the formula of adding within 20)?

B two digits plus one digit: first write down two digits to make a ten digit after integer ten, and then write down the remaining digits after dividing one digit by one. (that is, separate one digit and round two digits to ten digits)

Quick addition skill 15+8= process: 15+5=20 Write 2, 8 divided by 5, then leave 3, and then write 3. ?

Extended data:

Addition is exactly the same thing, that is, the repetition or accumulation of similar things, which is the beginning of numerical operation. Different kinds, such as an apple and an orange, can only be equal to two fruits, so there is a relationship between classification and classification.

Subtraction is the inverse operation of addition; Multiplication is a special form of addition; Division is the inverse operation of multiplication; Power is a simple form of multiplication; The root is the inverse operation of power; Logarithm is the law of finding power term; Derivative is developed from logarithm; Then differential and integral. The development of digital operation is a more special situation and a more repetitive law.

There are many binary operations that can be regarded as the generalization of real number addition. The field of abstract algebra focuses on these generalized operations, which also appear in set theory and category theory.

Addition in abstract algebra

Vector addition:

In linear algebra, vector space is an algebraic structure, and any two vectors and scale vectors can be added. The familiar vector space is the set of all ordered pairs of real numbers; Ordered pair (a, b) is interpreted as a vector from the origin in Euclidean plane to the midpoint (a, b) in the plane. The sum of two vectors is obtained by adding their respective coordinates:

This addition is the core of classical mechanics, in which vectors are interpreted as forces.

Matrix addition:

Defines matrix addition for two matrices of the same size. The sum of two m×n (pronounced "m times n") matrices A and B represented by A+B is a matrix calculated by adding elements, for example:

Addition in set theory and category theory

The way to increase natural numbers is to add ordinal numbers and cardinality to set theory. These give two different generalizations, namely, natural numbers. Unlike most addition operations, ordinal addition is not interchangeable. However, increasing cardinality is an exchange operation closely related to disjoint union operation.

In category theory, disjoint addition is considered as a special case, which may generally be the most abstract of all addition generalizations. For example, direct sum and wedge sum are called adding links.