Comprehensive scoring method:

1, find the least common multiple of the denominator of the original fraction;

2. According to the basic properties of the score, change the original score into a score with this least common multiple as the denominator.

Examples of general points:

① Divide 1/3 and 1/4.

Solution: The least common multiple of 3 and 4 is 12.

1/3 = 4/ 12

1/4 = 3/ 12

Then the scores are 4/ 12 and 3/ 12.

② Compare the sizes of 7/9 and 8/ 1 1.

Solution: 7/9 = 7×11/9×1= 77/99.

8/ 1 1 = 8×9 / 1 1×9 = 72/99

∫77/99 >72/99

∴7/9 & gt； 8/ 1 1

③ A: B = 2: 5 = 8: 20。

B: C = 4: 7 = 20: 35。

A: B: C = 8: 20: 35

Extended data

The key to general division is to determine the simplest common denominator of several fractions, and the steps are as follows:

1, which respectively lists the divisors of each denominator;

2. Multiply the divisor of the denominator. If there is a common divisor, the result is the least common multiple of the denominator;

3. All the letters or factors based on letters should be taken;

4. The factor with the same letter or the power of the factor with the letter takes the largest exponent;

5. Multiply all the above formulas to get the simplest common denominator.