What is the comparison of two quantities by division called?

The comparison of two quantities by division is called a ratio. A ratio expresses how much of one quantity is present compared to another quantity, and it can be written in several forms, such as a fraction, with a colon, or as a word statement.

For example, if there are 4 apples and 2 oranges, the ratio of apples to oranges can be represented as (4:2) or simplified to (2:1). This illustrates that for every 2 apples, there is 1 orange. The key aspect here is that a ratio inherently deals with the division of one quantity by another, yielding a relationship between the two.

Understanding ratios is important because they form the foundation for concepts such as rates and unit rates, which are specific types of ratios. A rate compares two different kinds of quantities, often with a specific unit of measure, while a unit rate refers to a rate with a denominator of one, simplifying the comparison further. However, these concepts stem from the basic idea of a ratio, making the term the most applicable choice in this context.