What is the term for a number that does not change when you add zero to it?

The term for a number that does not change when you add zero to it is known as the "Identity" element in mathematics, specifically in the context of addition. This is often referred to as the additive identity, which is the essence of how the identity property of addition works. According to this property, for any number ( x ), when you add zero to it, the result remains ( x ) (i.e., ( x + 0 = x )).

This concept is foundational in arithmetic, as it ensures that there is a base reference point (the number zero) which, when involved in addition, leaves other numbers unchanged. Understanding the identity property helps students grasp similar properties across different operations and deepen their comprehension of mathematical structures.