Knowledge of scientific numbering methods;

Write an integer whose absolute value is greater than 10 (or less than 1) in the form of a× 10 n (where 1 ≤/a/

Write an integer whose absolute value is greater than 10 (or less than 1) in the form of a × 10 n (where 1 ≤| a | < 10). This notation is called scientific notation. In the form of expression, methods such as 3.40282347e+38 are often used, where e+xx is the power of 10, and 3.40282347e+38 ==3.40282347 times the power of 10.

Characteristics of scientific numbering method:

Conciseness: It is scientific and simple to express a large number of numbers in the form of scientific notation.

The form of scientific notation consists of the product of two numbers.

One of the factors is a (1 ≤ A)

3. When using scientific notation to represent numbers, the symbols of numbers remain unchanged, only the writing form of numbers is changed.

A number is expressed as (a× 10 to the n power), where1≤ a.

In the form of power, it is sometimes convenient to express some large numbers encountered in daily life, such as: the speed of light is about 300,000,000 m/s; The world population is about 61000000.

Such a large number is inconvenient to read and write. Considering the power of 10, it has the following characteristics:

10 quadratic = 100, 10 cubic = 1000, 1000 quartic = 10000.

Generally, the power of 10 is n, and there are n zeros after 1, so some large numbers can be expressed by the power of 10, for example:

6100 000 000 = 6.1×1000 000 = 6.1×10 to the ninth power.

When there is a negative integer exponential power, positive numbers less than 1 can also be expressed by scientific notation. For example, the negative fifth power of 0.0000 1= 10, that is, a positive number less than 1, can also be expressed by scientific notation as a times the negative n power of 10, where a is a positive integer with only one bit and n is a positive integer.