1, decimal times integer: meaning-a simple operation to find the sum of several identical addends.
Calculation method: first expand the decimal into an integer; Calculate the product according to the law of integer multiplication; Look at a factor * * *, how many decimal places there are, and count the decimal points from the right side of the product.
2. Decimal multiplied by decimal: meaning-that is, what is the fraction of this number.
Calculation method: first expand the decimal into an integer; Calculate the product according to the law of integer multiplication; Look at a factor * * *, how many decimal places there are, and count the decimal points from the right side of the product.
Law: a number (except 0) is multiplied by a number greater than 1, and the product is greater than the original number; A number (except 0) is multiplied by a number less than 1, and the product is less than the original number.
3. There are generally three methods to find the divisor: rounding method; Become law; Tailing method.
4. Calculate the amount of money, and keep two decimal places, indicating that the calculation has reached the point. Keep one decimal place, indicating that the angle has been calculated.
5. The order of four decimal operations is the same as that of integers.
6. In practical application, the quotient obtained by fractional division can also be rounded to a certain number of decimal places as needed to get the approximate number of quotients.
7. Significance of fractional division: Know the product of two factors and one of them, and find the operation of the other factor.
8. Calculation method of decimal divided by integer: decimal divided by integer, and then divided by integer. The decimal point of quotient should be aligned with the decimal point of dividend. The integer part is not divided enough, quotient 0, decimal point. If there is a remainder, add 0 and divide it.
9. Calculation method of division with divisor as decimal: first expand the divisor and dividend by the same multiple to make the divisor become an integer, and then calculate according to the law of fractional division with divisor as integer.