1, which are all calculated by integer multiplication and division.

2. The multiplication and division of decimals and integers are done according to the law of multiplication and division of integers; Vertical, to align; If there is a remainder at the end of the dividend, fill in zero after the remainder and continue the division.

Difference:

Decimal multiplication is to calculate the decimal point from the right of the product according to the number of decimal places in the multiplier after obtaining the product. In fractional division, the divisor is first converted into an integer, that is, the decimal point of the divisor is shifted to the right by several digits, and the decimal point of the dividend is also shifted to the right by several digits. Then divide again according to the law of integer division to get the quotient, and then align the decimal point of the quotient with the decimal point of the dividend.

Endless decimal

A decimal with a finite number of digits after the decimal part. For example, 3. 1465, 0.364, 8.32 18798456, etc. All finite decimals belong to rational numbers and can be converted into component numbers.

A simplest fraction can be converted into a decimal finite fraction if and only if its denominator contains only prime factors 2 or 5 or both. Similarly, a simplest fraction can be transformed into a finite fraction of the base of a positive integer if and only if the prime factor of its denominator is a subset of the prime factor of the base.