Final answer:
The integer that describes the temperature being 15 degrees below zero is -15. This concept is important in mathematics for representing temperatures below the freezing point in both Celsius and Fahrenheit scales.
Step-by-step explanation:
To describe the temperature being 15 degrees below zero using an integer, we use negative numbers since temperatures below zero are represented by negative integers in math. The integer that represents 15 degrees below zero is -15. It's important to understand the concept of negative numbers when dealing with temperature scales like Celsius (C) and Fahrenheit (F), as both can include temperatures that fall below the freezing point (0°). In real-world scenarios, such as a cold front that drops the temperature or the final temperature of a mixture of water and ice, knowing how to work with integers and negative temperatures can be crucial.