There are two types of scores. One is the application problem of finding the fraction of a number (that is, finding the fraction of the unit 1 is known); The second is to know what the fraction of a number is and find the application problem of fractional division of this number (know what the fraction of unit 1 is and find unit 1).

Two:

Flexible use of arithmetic or equation to solve.

It is relatively simple to find the fraction of a number and multiply it directly by the fraction in the arithmetic method. Knowing what the fraction of a number is, it is easier to understand by solving it with equations.

Of course, the determination of the unit "1" mentioned by several people upstairs is definitely the key. There is a simpler way. The quantity after "Bi", "Yes" and "Equivalent" must be the unit "1". If the unit "1" is hidden, the first quantity, the initial quantity and the quantity before the change are all the same.