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.
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.
Vertical calculation
There are two main points in the calculation of column vertical pen: the same digit alignment, starting from the unit. You can add ten digits first without carrying, but it is not recommended for carrying addition later. The format of exercise books is strictly in accordance with the following requirements:
1, the horizontal formula is written from the left end of the horizontal grid line in the math book.
2. The first addend in vertical form is written under the second addend in horizontal form, and the plus sign is aligned with the plus sign in horizontal form. The same numbers of addend, addend and sum must be aligned.
3. After calculating the vertical columns, don't miss the horizontal numbers.