Here is a deceptively short mental-math puzzle: 160 + 40 × 0 + 9 = ? The image tells readers the answer is not 160. Is that correct?
Yes—the correct answer is 169
First, follow the order of operations. Multiplication comes before addition, so evaluate 40 × 0 = 0.
That leaves 160 + 0 + 9. Adding those numbers gives 169.
Why isn’t the answer 160?
The product of 40 and zero is zero, but the final + 9 doesn’t disappear. Some people stop calculating after adding zero, which makes them overlook the last part of the question. Others add 160 and 40 before multiplying, which ignores the multiplication-first rule.
The important point is to calculate the multiplication by zero, then finish the entire expression from left to right.
Try solving it aloud
Explain the puzzle in one sentence: “Forty times zero is zero, and one hundred sixty plus nine is one hundred sixty-nine.” If you got 169, your answer is correct. Try sending the puzzle to someone who likes quick math questions.
