(12) When a number is subtracted from itself, the answer is always the identity element for addition.

**True.** When you subtract a number from itself, the result is always **zero**. In the context of addition, **zero** serves as the *identity element*. An identity element is a special number that, when added to any number, leaves the original number unchanged. Here's a breakdown: - **Subtraction Example:** Let's take a number, say \( a \). \( a - a = 0 \) - **Additive Identity:** The additive identity is a number that, when added to any number, doesn't change its value. \( a + 0 = a \) Since subtracting a number from itself yields zero, and zero is the additive identity, the statement is **true**. **Summary:** - **Subtraction Result:** \( a - a = 0 \) - **Additive Identity:** \( a + 0 = a \) - **Conclusion:** The result of subtracting a number from itself is the additive identity (zero).