1. **State the problem:** Simplify the expression $1 - \frac{1}{2} \times 4$. 2. **Recall the order of operations:** Multiplication and division are performed before addition and subtraction. 3. **Calculate the multiplication first:** $$\frac{1}{2} \times 4 = \frac{1 \times 4}{2} = \frac{4}{2}$$ 4. **Simplify the fraction:** $$\frac{4}{2} = \cancel{\frac{4}{2}} = 2$$ 5. **Substitute back into the expression:** $$1 - 2$$ 6. **Perform the subtraction:** $$1 - 2 = -1$$ **Final answer:** $-1$