1, indirect method
First, the decimal number is converted into a binary number by dividing the remainder by 8, and then the binary number is converted into an octal number. Specific steps:
(1) Converts a decimal number into a binary number by dividing it by 8 and taking the remainder. For example, the decimal number 43 can be converted into a binary number in the following ways: 43/2 = 2 1 and1->; 10 10 1 1。
(2) The obtained binary number is further converted into octal number. This step can be converted by every three binary numbers, which is the third power of 2. For example, binary number10101can be converted into octal number as follows: 010100->; Therefore, decimal number 43 is converted into octal number 254 by indirect method.
2. Direct instruction
Divide the decimal number of 10 by 8 to get quotient and remainder, divide the quotient by 8 until the quotient is 0, and finally arrange all the remainder in reverse order to get octal number. Specific steps:
(1) Divide the decimal number by 8 to get the quotient and remainder. For example, for the decimal number 43, the calculation is as follows: 43/8 = 5+3.
(2) Divide the quotient by 8 until the quotient is 0, and record the remainder of each division. These remainders will form the numerical order of octal numbers. For example: 5/8 = 0 and 5->; Therefore, the first digit of the octal number is 5.
(3) arrange all the remainders in reverse order to get the final octal number. Therefore, for the decimal number 43, the resulting octal number is 53. Therefore, the decimal number 43 is converted into the octal number 53 by the direct method.
Key knowledge of mathematics? ：
In the field of algebra, the emphasis includes the solution of equations, such as univariate quadratic equation and bivariate quadratic equation, as well as the simplification and factorization of algebraic expressions. In the field of geometry, the emphasis includes the nature and classification of graphics, the calculation of area and volume, and coordinate geometry.
In the field of probability statistics, it mainly includes the basic concept of probability, probability distribution, statistical inference and so on. In the field of calculus, it mainly includes basic concepts such as limit, derivative and differential, integral and their applications.
For example, for the quadratic equation AX 2+BX+C = 0, the solution method includes the formula X = [-B sqrt (B 2-4ac)]/(2A), which can solve practical problems such as 2x 2-4x-6 = 0. In the field of geometry, the properties and judgment theorem of parallelogram are one of the key points. For example, a parallelogram can be judged by the parallelism of two straight lines, and its properties and judgment methods can be mastered at the same time.