Simple operation Su Jiaoban was learned in the fifth grade. Simple operation is a special kind of calculation, which makes use of the algorithm and the basic properties of numbers, thus making the calculation simple and making it easy to calculate numbers from very complicated formulas.

Multiplicative distribution law:

The most commonly used method in simple calculation is multiplication and distribution law. Multiplication and division means ax(b+c)=axb+axc, where A, B and C are arbitrary real numbers.

On the contrary, axb+axc=ax(b+c) is called the inverse application of multiplication and division (also called finding common divisor), especially when A and B are complementary to each other, this method is more useful.

Sometimes the law of additive combination is used, for example, a+b+c, and B and C are complementary, so that B and C can be combined and multiplied by A. If+in the above formula is replaced by X, it can also be simply calculated by the multiplicative associative law.

Law:

Multiplicative commutative law;

Multiplicative commutative law is used to exchange the positions of various numbers: a× b = b× a.

Additive commutative law;

Additive commutative law is used to exchange various numbers: a+b = b+a.