The answer isn’t 16? This math puzzle is sparking discussion.
At first glance, the task looks surprisingly simple:
2 × 2 + 2 × 3!
Above it is the provocative statement: « The answer is NOT 16! » This sentence is precisely what makes the puzzle interesting. Many people immediately begin to question their calculations, even though the mathematical rules actually dictate a clear procedure.
Is there actually a hidden trap built in somewhere? Do you have to calculate differently than you initially think? Or is the wording simply an attempt to distract us from what is actually a simple solution?
To find out, you have to take a closer look at the small mark after the 3. The exclamation mark here isn’t simply a punctuation mark. In a mathematical problem, it has a very specific meaning.
Consider the task step by step
The complete task is:
2 × 2 + 2 × 3!
Anyone who overlooks the exclamation mark or interprets it as a decorative symbol could calculate the problem completely differently. That’s precisely why it’s worthwhile not to start calculating immediately, but to first identify all the mathematical symbols.
What does 3 mean!?
The exclamation mark after a number denotes the factorial. In 3!, the positive integers from 3 to 1 are multiplied together.
Therefore:
3! = 3 × 2 × 1 = 6
That’s the crucial point of the puzzle. The number 3 isn’t simply treated like any other 3. First, its factorial must be calculated.
Which arithmetic operation comes first?
Besides the factorial, the expression contains multiplications and an addition. Here, too, fixed mathematical rules apply to the order of calculation.
The factorial is evaluated first. Then the multiplications are performed, before the addition is carried out finally.
Therefore, let’s first insert the value of 3 !:
2 × 2 + 2 × 6
Now the two multiplications are calculated:
- 2 × 2 = 4
- 2 × 6 = 12
This leaves:
4 + 12
And from this follows:
16
Why does the image then claim that the answer is not 16?
See more on the next page