Have you ever scrolled through social media and stumbled upon a math puzzle that looks ridiculously simple at first glance?
Most of us look at these challenges and think we can solve them in three seconds flat.
Then, we open the comment section and find thousands of people fiercely arguing over completely different answers.
The handwritten note in the picture presents us with a classic brain teaser: “40 + 40 – 70 × 0 + 20 + 110 = ?”.
It also comes with a direct challenge: “Try to calculate without a calculator.”
At first sight, your brain might tell you that this is just basic elementary school arithmetic.
However, simple math problems often hide clever traps that easily trip up even the smartest adults.
The biggest trap in this equation is the number zero sitting right next to the multiplication sign.
Many people quickly scan the problem, spot “× 0”, and assume that everything turns into zero.
They believe the entire front half vanishes instantly, which leads them straight to an incorrect result.
Another common mistake happens when people calculate strictly from left to right, like reading a book.
If you just go from left to right, you will add 40 and 40 to get 80, subtract 70 to get 10, and then multiply by zero.
That leaves you with zero, plus 20, plus 110, giving an answer of 130.
While that sounds neat and straightforward, mathematics does not work that way.
In math, there is a fundamental traffic rule known as the order of operations, often called PEMDAS or BODMAS.
This universal rule tells us which operation gets VIP treatment and must be solved first.
Parentheses and exponents always go first, followed immediately by multiplication and division.
Only after all multiplications and divisions are finished can we move on to addition and subtraction from left to right.
Now, let us look at our equation again with this golden rule in mind.
There are no brackets and no exponents, but there is one multiplication: 70 multiplied by 0.
Any number multiplied by zero equals zero, so “70 × 0” simply becomes 0.
Notice that the multiplication only belongs to the 70 right before it, not to the whole expression.
Now we can rewrite the entire line cleanly: 40 + 40 – 0 + 20 + 110.
All that remains are simple additions and subtractions, so we can finally move smoothly from left to right.
First, we take 40 + 40, which equals 80.
Next, we subtract 0 from 80, which still leaves us with 80.
After that, we add 20 to 80, bringing our running total to exactly 100.
Finally, we look at the last number, which is 110 split across the two lines on the paper.
We add 110 to our current total of 100.
100 plus 110 gives us 210.
That is our solid, logical, and indisputable final answer.
The correct result to this fun puzzle is 210.
Putting down the calculator for a moment is a great reminder of how satisfying simple logic can be.
