What term is often used to describe the relation of two quantities as a division?

The term that describes the relation of two quantities as a division is "ratio." A ratio expresses how many times one quantity is contained within another, which is fundamentally a comparison between two numbers. Mathematically, if you have two quantities, you can find their ratio by dividing one by the other. For example, if you have 4 apples and 2 oranges, the ratio of apples to oranges is 4:2, which can also be simplified to 2:1. This conveys how the two quantities relate to each other in terms of proportion.

In contrast, the other terms refer to different mathematical operations or concepts. The term "sum" refers to the result of adding two or more quantities together, "division" refers to the mathematical operation of dividing one number by another without the relational context, and "subtraction" refers to the operation of taking one quantity away from another. Thus, "ratio" is the most accurate term for describing the relationship of two quantities through division.