If I asked you to tell me what 16% of 25 is, you'd almost definitely pull up the calculator on your phone. I certainly would.
Which is why a simple math trick that was just posted on Reddit is blowing people's minds. And it is: Percentages are reversible.
So 16% of 25 is the same thing as 25% of 16. The second one is a lot easier to figure out . . . it's four. We can do that in our heads.
Now, the trick isn't great for numbers where you can't do either percentage in your head . . . like 17% of 39 or 39% of 17. (It's 6.63.) But for lots and lots of other numbers, it's a good trick.
How am I just now learning this??!
[Yahoo]
Image: Getty Images