1, decimal divided by integer, 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.

2. In practical application, the quotient obtained by fractional division can also be "rounded" to a certain number of decimal places according to needs, so as to obtain the approximate number of quotients.

3. 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.

4. The decimal part of a number starts from a certain place, and one or several numbers appear repeatedly in turn. Such decimals are called cyclic decimals.

5. The digits in the decimal part are finite decimals, which are called finite decimals. The number of digits in the small book part is infinite decimal, which is called infinite decimal.

6. There are usually three ways to find the approximate value:

⑴ Rounding method: To find the divisor of a number, it mainly depends on whether the number of the highest digits omitted by it is less than 5, greater than 5 or equal to 5. If the highest digit of the omitted mantissa is 4 or less, all mantissas are discarded. If the number on the highest digit of the omitted mantissa is 5 or more, the mantissa is omitted and then advanced by one digit.

⑵ One-to-one correspondence method: In practical problems, sometimes, after the mantissa of a number is omitted, 1 should be input to its previous digit regardless of the number of the highest digit quotient. For example, put 400 kilograms of grain into sacks. If each sack can only hold 75 kilograms, how many sacks do you need at least Because 400 ÷ 75 = 5.33 ... That is to say, 400 kilograms of grain is packed in five sacks, leaving 25 kilograms. The 25 kilograms need to be packed in a sack, so one * * * needs six sacks. That is 400 ÷ 75 = 5.33. .........................................................................................................................................................

⑶ Truncation method: In practical problems, sometimes, after the mantissa of a number is omitted, it is not necessary to input 1 before it, regardless of the number of quotient of the highest digit. For example, 200 sheets of paper are bound into a book, and each book is 12 sheets. How many books can be bound? Because 200 ÷ 16 = 16.66 ... that is, 22 sheets of paper are bound into 16, and there are still 8 chapters left. According to the requirements in the title, 12 sheets can be bound into a book, and the remaining 8 sheets cannot be bound into 12 sheets. Namely: 200 ÷16 =16.66 ... ≈16 (Ben). This method of finding the divisor is called truncated method.

7, adult male standard weight = height-105

8. An equation with an unknown number is called an equation.

9. The value of the unknown that makes the left and right sides of the equation equal is called the solution of the equation.

10, the process of solving the equation is called solving the equation.

1 1, Fahrenheit = × 1.8+32.

12, area of parallelogram = bottom× high letter formula: S=ah.

13, triangle area = base × height ÷2 letter formula: S=ah÷2.

14, trapezoidal area = (upper bottom+lower bottom) × height ÷2 letter formula: S=(a+b)h÷2.

15, the advantage of median is that it is not affected by the data size, and it is more suitable to represent the approximate level of all data.

16, numbers can be used not only to indicate quantity and order, but also to code.