1 in 10 can do this calculation without a calculator… are you up for the challenge?

The answer:

And there you have it: the correct answer is   38.  Easy? Yes, once you remember the basics!

Why we love this kind of challenge

If this type of topic goes viral, it’s no coincidence. It has all the makings of an attention-grabber:

• It’s easy to understand.
• It seems too simple to be true, which piques curiosity.
• Create a small challenge for yourself or with friends.
• And most importantly, when you solve it correctly, you get great satisfaction!

It’s also a fun way to re-learn math: no long formulas or abstract concepts, just a little logic and rigor.