If you subtract 30 from 30, what do you get?

When you subtract 30 from 30, you are essentially calculating 30 - 30. This operation means you are finding out how much is left when you take away all of the quantity you started with. In this case, you are removing the entire value of 30, leaving you with none. Thus, the result of this operation is 0.

In mathematical terms, subtracting a number from itself always results in zero because you are neutralizing that quantity. This principle is foundational in arithmetic and holds true for all numbers. Therefore, 0 is the correct and logical answer to this question.