Vertical decimal multiplication: the last digit is aligned and calculated according to the calculation rules of integer multiplication. After calculating the product, see how many decimal places one of the two factors has, and then count the decimal points from the right side of the product. If there is a zero at the end, you can remove it.

Vertical decimal division: mainly depends on divisor. The divisor is a few decimal places. Just expand the divisor by the same multiple at the same time to make it an integer, and calculate it according to the law of integer division.

Arithmetic of decimal multiplication:

1, first quadrature according to the law of integer multiplication.

2. See how many decimal places the multiplicand and multiplier * * * have. Just count the numbers from the right side of the product and point to the decimal point.

3. If there is a 0 after the decimal point, cross out the 0 after the decimal point according to the basic properties of the decimal point.

Decimal multiplication and division calculation rules:

1, decimal multiplication calculation rules:

First, calculate the product according to the calculation rules of integer multiplication, and then look at the factor * * * and how many decimal places there are. Just count the numbers from the right side of the product and point to the decimal point. If the number of digits is not enough, use "0" to make it up.

2, decimal division calculation rules:

First, move the decimal point of the divisor to make it an integer, then move the decimal point of the divisor to the right by several digits (if there are not enough digits, add "0"), and then calculate according to the division rule that the divisor is an integer.