The general score is to change the scores of several different denominators into the same denominator, and the size of the scores remains the same. Finding the common denominator requires knowing the least common multiple of several denominators. Use the least common multiple of several fractional denominators as the common denominator. To find the common denominator, we should pay attention to the characteristics of several denominators and flexibly use the method of finding the least common multiple.

(1) Large numbers are multiples of decimals, and large numbers are their least common multiples.

(2) Two numbers are prime numbers, and the product is their least common multiple.

(3) If several numbers have the same divisor, find the least common multiple by short division. Or multiply and double. When two of the three numbers have multiples, you can temporarily give up the smaller number and only consider the least common multiple of the big number and another number, that is, the least common multiple of these three numbers.

Method of restoration:

Generally, the common factor of the numerator and denominator (except 1) is used to divide the numerator and denominator of the fraction until the simplest fraction is obtained.