=600×600+600×20+600×5+20×600+20×20+20×5+5×600+5×20+5×5

=360000+ 12000+3000+ 12000+400+ 100+3000+ 100+25

=390625

The vertical calculation is as follows:

Extended data:

625 is decomposed into 600+20+5, and 625×625 is decomposed into (600+20+5)×(600+20+5), so the product of 625×625 can be calculated by using the algorithm of algebraic formula (a+b+c)×(a+b+c).

Operation, mathematically speaking, operation is the act of obtaining new quantities through possible combinations of known quantities. The essence of operation is the mapping between sets.

Generally speaking, operation refers to algebraic operation, which is the correspondence in a set. For a pair of elements A and B taken out in sequence in set A, there is a unique third element C corresponding to it in set A, which is called the operation defined in set A..

From this operation, we can get two operations, that is, one of A and B is expected and C is known. The operation thus obtained is called the inverse operation of the original operation.

For example, addition is the operation of finding a+b=c when A and B are known, then the operation of finding B when A and C are known, or the operation of finding A when B and C are known, is the inverse operation of addition, which is called subtraction.

Formulas obtained by finite algebraic operations such as addition, subtraction, multiplication, division, multiplication and square root of numbers and letters representing numbers or mathematical expressions containing letters are called algebraic expressions. For example: ax+2b, -2/3, b 2/26, √a+√2, etc.

Baidu Encyclopedia-Operation (Mathematical Concept)

Baidu encyclopedia-algebraic expression