What mathematical concept represents comparisons of two quantities?

The concept that represents comparisons of two quantities is best exemplified by ratio. A ratio is a relationship between two numbers indicating how many times the first number contains the second. It expresses the relative size of two values and is often written in the form of a fraction, such as 3:2, which shows the relationship between the two quantities.

Ratios are particularly useful because they provide a straightforward way to compare quantities directly, facilitating an understanding of the relative sizes of the quantities involved. For instance, if one recipe calls for 2 cups of flour and another calls for 3 cups, the ratio of flour used is 2:3, clearly demonstrating the comparison between the two amounts.

Other concepts such as fractions, proportions, and percentages also involve comparisons, but they do so in different contexts. A fraction represents a part of a whole, a proportion compares two ratios, and a percentage expresses a number as a fraction of 100. While these concepts are related and sometimes intertwined, it is the ratio that directly defines the comparative relationship between two distinct quantities in their simplest form.