In this example, speed is key: 30 - 12 ÷ 3 × 2 = ? The correct answer is in the first comment. 👇

 

Solve this problem: 30 – 12 ÷ 3 × 2 = ?

This seemingly simple calculation hides a classic trap that fools even the most astute minds. Will you be able to avoid the mistake and outsmart the automatic responses?

Think simple calculations are the easiest? Think again… Behind a seemingly innocuous operation lies a formidable trap that makes even the most confident hesitate. Between automatic responses and haste, our brains love to play tricks. What if this simple exercise actually revealed a habit that almost all of us have without realizing it?

Why does this calculation mislead so many people?

When faced with an operation like 30 – 12 ÷ 3 × 2, the first instinct is often to read from left to right, as one would with a sentence. The result: we string together calculations without thinking about their order… and that's where everything goes wrong.

It's a bit like following a recipe but mixing up the steps: even with the right ingredients, the result can be a complete disaster! In mathematics, each operation has its priority, and ignoring them is like skipping an essential step.

The problem isn't a lack of skill, but rather a deeply ingrained habit: going too fast. And let's face it, in our hectic daily lives, taking the time to think through such a simple calculation doesn't always seem necessary…

The essential rule you absolutely must know

To avoid any confusion, simply remember a key rule learned at school (and sometimes a little forgotten):
division and multiplication are always performed before subtraction and addition.

No need for a complicated formula, just a logical order to follow. Think of it like a priority queue: some operations take precedence over others.

In our case, this means that we definitely do not start with 30 – 12. No, we first deal with what happens between 12, 3 and 2.

Step-by-step solution to avoid making mistakes again

Let's take the time to break down the operation calmly:

12 ÷ 3 = 4
4 × 2 = 8

Once these steps are completed, the expression becomes much simpler:

30 – 8 = 22

And there you have it!  The final result is 22.

Simple, right? But you still had to follow the right order.

The most common mistake (and how to avoid it)

Many people make the following mistake:
they start directly with 30 – 12, which gives 18, and then continue the calculations. But this method doesn't respect the order of operations… and leads to the wrong answer.

To avoid this trap, adopt a simple little habit:
before calculating, identify the divisions and multiplications in the operation.

It's like highlighting the important steps in a text: your brain immediately understands where to start.

An excellent exercise to train your attention

This type of calculation is much more than a simple school exercise. It highlights something very common: our tendency to go too fast.

In everyday life, this can translate into oversights, mistakes, or decisions made a little too hastily. Taking a few seconds to check can make all the difference.

You can even turn this into a little game: test your friends or colleagues with this exercise. The answers might surprise you!

And you, did you find it on the first try?

No judgment here! Whether you found 22 immediately or not, the important thing is to understand the mechanism behind the mistake.

With a little attention and keeping this rule in mind, you will no longer be trapped by this kind of calculation.

And the next time you come across a "too easy" operation, you'll know that it might deserve a second look.

Sometimes, the simplest things teach us the most.