Social media has a way of making everyday things go viral—especially when it comes to brain teasers and math puzzles that stump even the best of us. One recent viral brain teaser asked people to solve this seemingly simple math problem: 230 – 220 x 0.5. The surprising twist? Most people would guess wrong on their first try, and it turns out that the answer is actually 5. Now, before you scoff or think this is just clickbait, let’s take a closer look at why so many people get this wrong and how to arrive at the correct answer.

These kinds of math problems are often called brain teasers because they really force you to slow down and think carefully about how you apply basic math rules. And, let’s face it—brain teasers like this one are exactly why so many social media users find themselves spending hours trying to figure out an answer that makes sense. It’s a fun way to take a break from the stresses of daily life, challenge your mind, and perhaps even show off a little bit if you get it right.

The thing about this math problem is that it’s simple enough that it tricks you into thinking you don’t need to pay close attention. In fact, most people jump straight in and overlook the rules that govern basic arithmetic. The problem reads:

230 – 220 x 0.5 = ?

At first glance, it’s easy to make a mistake if you don’t apply the proper rules of arithmetic, which dictate the order of operations. These rules are known as PEMDAS in the United States. PEMDAS is an acronym that stands for Parentheses, Exponents, Multiplication and Division (from left to right), Addition and Subtraction (from left to right). These are the steps we must follow to solve any math expression.

In this particular problem, 230 – 220 x 0.5, there are no parentheses or exponents, so we jump straight to multiplication and division. According to PEMDAS, multiplication must be performed before subtraction. That means we need to multiply 220 by 0.5 before doing anything else.

So, let’s solve it step by step:

Step 1: Multiply 220 by 0.5
220 x 0.5 = 110

Step 2: Subtract the product from 230
230 – 110 = 120

So, the straightforward answer is 120. However, this is where it gets interesting. Why is everyone saying the answer is 5? Where does that number even come from?

The answer lies in a playful twist that often accompanies viral puzzles like this one. Math enthusiasts and puzzle creators like to add a touch of misdirection and creativity to their explanations. Let’s dive a bit deeper.

If you look at 5 factorial, written as 5!, it’s the product of all positive integers from 5 down to 1. To calculate 5 factorial, you would do the following:

5 x 4 x 3 x 2 x 1 = 120

The result is 120, which matches our earlier answer. The key point here is that 120 is also 5! (read as “five factorial”). The use of the exclamation mark isn’t just for emphasis—it’s an actual mathematical operator that indicates a factorial. So, when the puzzle states that the answer is 5, it’s actually playing on the concept that 120 can be represented as 5 factorial.

This twist is what makes the problem go viral and leaves many people scratching their heads. It’s not that the original answer was wrong—it’s just that there’s a clever secondary meaning that ties into factorials and makes the whole thing a little more interesting.

To recap:

The initial math problem, 230 – 220 x 0.5, when solved using the proper order of operations (PEMDAS), results in 120.
This 120 is the product of 5 x 4 x 3 x 2 x 1, which is written as 5! or 5 factorial.
The statement that “the answer is 5” refers to the factorial representation of 120, which is derived from 5.
These types of puzzles are great for reminding us why understanding mathematical rules is important—not just for solving problems but also for having fun with numbers. They can be tricky and misleading at times, but that’s exactly what makes them so enjoyable. The key is to approach them with patience and remember the basics of math that we all learned in school.

So, next time you see a math puzzle like this pop up on your social media feed, take a moment to think about the order of operations. And if the answer doesn’t seem to make sense at first, consider whether there’s a clever twist hidden beneath the surface. In the end, puzzles like this are less about getting the answer right on the first try and more about enjoying the process of figuring it out—and maybe learning something new along the way.

Let me know if there are any adjustments or further edits you’d like!