There are 45 books in the third grade math corner, two fifths of which are story books.

Answer:

45x2/5= 18 copies

A: There are 18 story books.

Extended data

Fractional mixed operation. The operation order of fractional mixing operation is the same as that of integer, and it should be changed to the same denominator if it is not the same denominator. When two or more fractions are added or subtracted, you can choose one-time or step-by-step division, and the final result is the simplest fraction. According to different situations, choose different calculation methods.

Method of sharing:

1, find the common denominator. (The common denominator can be the least common multiple of two or more numbers. )

2. Then change the denominator of two or more fractions that need division from different denominators to the same denominator. According to the basic properties of fractions: the numerator and denominator of fractions are multiplied or divided by the same number at the same time (except zero), and the size of fractions remains unchanged.