Only brilliant minds can solve this puzzle in less than 10 seconds.

7 × 7 ÷ 7 – 1 + 7. Sounds basic, right? And yet… this kind of equation circulates on social media with a challenge: "Find the answer in less than 10 seconds." The result? More than half the people get it wrong. Did you also dive headfirst into the calculations? Hold on… it might not be as easy as it seems. One crucial detail changes everything.

The order of operations: the golden rule too often forgotten

Behind this sequence of numbers lies a well-known trap:  the order of operations .  A classic in mathematics, but one easily forgotten in adulthood.  Yet, a single mistake is enough to invalidate the entire equation.

In France, we learn to follow the  PEMDAS/BODMAS method  (Parentheses, Exponents, Multiplication/Division, Addition/Subtraction).  It may seem academic, but in reality, it's simpler than it appears:

• Parentheses  : we always start with what is in parentheses.
• Exponents  (or powers): squares, cubes, etc.
• Multiplication and division  :  in order of appearance, from left to right.
• Addition and subtraction  : same,  we follow the order of reading.

And that's where everything changes. Because if you've done the operations out of order, your result is… wrong.

Decoding: Step-by-step instructions to avoid being fooled again

Let's take our equation:
7 × 7 ÷ 7 – 1 + 7

Step 1 – Multiplication and Division

We begin with these operations,  in the order in which they appear  :

7 × 7 = 49
49 ÷ 7 = 7

The equation therefore becomes:
7 – 1 + 7

Step 2 – Addition and Subtraction

Always from left to right:

7 – 1 = 6
6 + 7 =  13

Final answer: 13

And there you have it.  Simple… but only if you follow the steps in the right order!

Why do we so often fall into this kind of trap?

We often think that math  is all or nothing  : you either love it or you hate it. But this kind of little challenge puts everyone on the same level:  you think you've got it figured out… and you get caught out by the speed, the stress, or a vague memory of the calculation rules.

The result? We calculate in our heads,  we skip steps, and we make mistakes.  Sometimes even completely.

A tip to avoid making the mistake: slow down!

The real secret isn't reciting  PEMDAS or BODMAS by heart.  It's taking your time.  The most common mistake is reading too quickly, solving out of order… and the trap snaps shut.

So the next time you come across a calculation like this:

• Take a deep breath.
• Identify the priorities ( multiplication and division first! )
• Solve each step  without skipping any.
• Read your answer again.

It's  like a cooking recipe  : if you mix everything in any order, the result will never be up to scratch.