Wanna follow me down a little rabbit hole I discovered recently? On how Google amplifies one internet user's innocent math error.

Let's say you want to know how much all the land of Central Park in NYC is worth (yes, I sometimes google stuff like that).

Google, as it increasingly does, doesn't simply give a list of websites that might contain an answer. It puts the answer front and center. 39 trillion dollars. Wow, that's...even more than I would have expected.

Now, Google shows where it got that number from ( @guardian, a trustworthy source) and even provides the calculation that results in that huge number. Let's do the math.

39 million square feet times $1000/square foot equals...39 billion. Not trillion. 1000 times less. Oh!

Let's follow that link then and double-check: https://www.theguardian.com/notesandqueries/query/0,,-62724,00.html. The page looks a bit dated and it seems to be part of The Guardian's «Notes and Queries» series, «that invites readers to send in questions and answers». And sure enough, there it is:

In this context, it becomes clear that we're looking at a back-of-the-envelope calculation, submitted by a Guardian reader (Hi, Jay!). In Google's answer box, that wasn't apparent.

Now, I know very little about real estate, so I have no way of knowing whether $1000/sqft is a good guesstimate. But even if it was off by a factor of 10, that error would pale against the simple math error Jay did when multiplying 39 million with 1000.

(By the way, 848 acres is more like 37 million square feet, but let's be generous here. And also, Google tells me Central Park is 840 acres in that answer box, but let's not follow the rabbit hole within the rabbit hole.)

Let's have a look at the other answers submitted on that Guardian page. Turns out that two other people did very similar calculations, but without the math error. One answer is above the one Google picks, one below.

So, to summarize: Don't take those Google answers at face value. It might literally be taken off a 10+ year old page, submitted by a random internet user, who happened to make a simple math error.

And yes, I do know that sometimes, things on the internet are not correct. But it is Google's unique position and the way those answers are presented that make them appear credible and allow them to spread easily.