At first glance, it looks like an ordinary math problem that almost anyone could solve in seconds. Written in dark ink on a piece of aged paper is a short equation: 8 − 2 × 3 + 6 = ? Above it, someone has written a warning that immediately catches your attention: “The answer is not 24!” But why would such a simple calculation cause so much confusion?

Many people confidently arrive at 24 because they solve the equation from left to right. First, they subtract 2 from 8, leaving 6. Next, they multiply 6 by 3 to get 18. Finally, they add 6, producing 24. The calculation seems perfectly reasonable until you remember one important mathematical rule that many of us learned in school.

The trick isn’t hidden in the numbers themselves. It’s hidden in the order in which you perform the calculations. Mathematics follows specific rules, and ignoring even one of them can completely change the result. That’s why a problem involving only four small numbers can generate several different answers.

Before reading further, take another look at the equation. Try solving it without a calculator, and think carefully about which operation should come first.

Did you get 24, 8, or something completely different? There’s one simple rule that reveals the correct answer.

Continue below in Part 2.