Which of the following is true about comparing fractions?

Comparing fractions often involves understanding their values in relation to one another, and using common denominators is a fundamental technique in this process. When two fractions have different denominators, it can be challenging to determine which is larger or smaller directly. By converting them to have the same denominator, you create a common reference point that allows for straightforward comparison.

Once the fractions share a common denominator, you can compare the numerators to see which fraction is greater or if they are equal. This method simplifies the process and is particularly effective because it eliminates variations caused by differing denominators.

Using numerators alone without adjusting for the denominators can lead to incorrect conclusions, as the size of the denominator impacts the overall value of the fraction. Similarly, while the least common multiple (LCM) can play a role in finding a common denominator, it is not the standard method used for straightforward fraction comparison in most educational contexts.

The focus on common denominators aligns with the way fractions are typically taught and understood in arithmetic, making this the correct choice.