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Qingdao edition mathematics case
As long as it is a fractional division problem, find the unit 1 first. The unit 1 is found and the method comes out.

There are many types of fractional application problems, which can be roughly divided into three categories in primary school:

(1) How much is one number more or less than the other?

Example: How much is 20 less than 35? 1/2 is more than 2/3?

Formula: the difference is "1"

Solution: (35-20) ÷ 35 (2/3-1/2) ÷1/2.

(2) If two quantities know one of them, and one quantity is more or less than the other quantity, find the other quantity.

Formula: unit 1 Know multiplication but not division. If you add more and subtract less, you will get another quantity.

Example: There are 300 students in grade five, and the number of students in grade six is more than that in grade five 1/2. How many students are used in the sixth grade?

300×( 1+ 1/2)

Example: There are 300 students in grade five, less than those in grade six 1/3. How many students are there in the sixth grade?

300÷( 1- 1/3)

(3) Unit 1 I don't know how to divide it. Divide the corresponding number by the corresponding score in 1.

These third problems account for more than 70% of the application problems of fractional division.

There are 300 students in grade five, which is 2/5 of the number in grade six. How many students are there in the sixth grade?

300÷2/5

Example: To build a road, 1/5 was built on the first day, 500m was built on the second day, and the remaining 1/4 was not repaired. How many meters is the total length?

500÷( 1- 1/5- 1/4)

I'm just talking about the above three types. If you are smart enough, you can definitely draw inferences from the other. When you see a fractional application problem, first analyze which one it belongs to, and then hit the target with the corresponding method. Ha ha! I hope I can help you.