How do you multiply decimal numbers by whole numbers? How do you calculate decimal multiplication by

1. It is not the same digit alignment, but to consider the decimal multiplication of the integer as an integer multiplied by an integer to write the vertical formula (reason: we are solved by converting the decimal multiplication integer into an integer multiplied by an integer, and the vertical calculation should be carried out according to the integer multiplied by the integer, because the integer multiplication method is the same digit alignment, and the single digit is aligned with the single digit, that is, the last digit is aligned, so the decimal multiplication integer should be consistent with the vertical format of the integer multiplied by the integer, which is convenient for calculation. ）

2. Perform vertical calculation according to integer multiplication by integer (treat decimal numbers as integers).

3. After the result is calculated, you need to consider the position of the decimal point of the product (how many decimal factors are multiplied, and the result of multiplying the integer just now is obtained after multiplying the original product. To request the original product, you need to divide the product of the integer by this number, with the decimal point moving to the left).

4. After counting the decimal point, see if there is 0 at the end of the product, if there is 0, you need to simplify it (cross out the 0 at the end in the vertical form, and write the result of simplification horizontally).

Multiply the decimal by an integer.

There are no special rules of calculation.

It is to multiply two integers first.

Then follow the number of decimal places.

Just move the relative decimal point.

First of all, the decimal number is an integer, then you can, the final result can be dotted to a decimal point, there are several decimal places, after the decimal point, let it be a few decimal places.

Decimal multiplication integer calculation method: first remove the decimal point, and then calculate according to the law of integer multiplication of integers, and finally see how many decimal places there are in the factor, and then count out a few from the right side of the product, point to the decimal point, when the number of digits is not enough, add "0" to make up.

Multiplying decimals by integers is not the same as multiplying integers by integers. One of the factors in a decimal multiplied integer is a decimal place, so the product is also a decimal in general. In decimal multiplication, if there is a 0 at the end of the decimal part of the product, the 0 at the end can be removed according to the basic properties of the decimal, and the 0 at the end of the integer multiplication cannot be removed.

The steps for multiplying decimal numbers by integers are as follows:

1. The numbers should be aligned, and the multiplication sign should be written in front of the numbers below

2. Enlarge the decimal by a certain multiple and turn it into an integer (one decimal point will expand by 10, two decimal places will be expanded by 100 times, and so on), and then multiply according to the integer multiplication, as shown in the following figure:

3. According to the integer multiplication, the following results are obtained:

4. Look at how many decimal places there are in the multiplier and multiplier, and count the number from the right side of the product and point to the decimal point. If there is a 0 at the end of the decimal, cross out the 0 at the end of the decimal according to the basic macro quality of the decimal envy.

The calculation rule of decimal multiplication by integer is to calculate vertically according to the law of integer multiplication by integer, and then see how many decimal places there are in the factor, count out the number from the right side of the product, and point to the decimal point; Multiplying decimal numbers by integers has the same meaning as integer multiplication, which is a simple operation to find the sum of several identical additions, such as expressing the sum of 5 or 5 times.

Mutual decimalization:

1. Fractional fractions.

It turns out that there are several decimals, and a few zeros are written after 1 as the denominator.

Remove the decimal point from the original decimal point as a numerator, and offer points that can be reduced.

2. Fractions are decimalized.

Remove the numerator with the denominator. What can be divided into a finite decimal, and some can not be divided, and if it cannot be divided into a finite decimal, it is generally kept to three decimal places.

3. Reducing finite decimals.

A minimal fraction.

If the denominator contains no prime factors other than 2 and 5.

This fraction can be reduced to a finite decimal; If the denominator contains a prime factor other than 2 and 5, the fraction cannot be reduced to a finite decimal.

4. Decimal into percentages.

Just move the decimal point two places to the right and add a percent sign after it.

5. Percentages are converted into decimals.

To convert percentages to decimals, simply remove the percent sign and move the decimal point two places to the left.

The rules of decimal multiplication are: 1. Calculate the product according to the rules of integer multiplication. 2. Look at how many decimal places there are in the factor, count the number from the right side of the number, and point to the decimal point. 3. There is 0 at the end of the decimal part of the number, and the 0 should generally be removed.

Decimals are a special form of representation of real numbers. All fractions can be expressed as decimals, and the dot in the decimal is called the decimal point, which is the dividing point between the integer part of a decimal and the decimal part. A decimal with an integer part of zero is called a pure decimal, and a decimal with an integer part that is not zero is called a decimal with a decimal.