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August 5th, 2019

PEMDAS results

Here's a simple math question that befuddled the Twitterverse last week: 8/2(2+2)=?

If you came up with 1, you did the addition first, then multiplied the result by two before finally dividing. And you are wrong.

The correct answer is 16. Why? Well, because Cornell math professor Steven Strogatz says so in The New York Times. And because of PEMDAS.

Remember PEMDAS from junior high? It's the rule about the order in which you work math operations: parentheses, exponents, multiplication, division, addition, subtraction.

There's a qualifier to the rule, which is where the math geeks exploded -- multiplication and division have equal priority. In a tie, you work left to right. Same thing with addition and subtraction.

Applying PEMDAS and the left to right priority rule, Strogatz says you add the parentheses first -- 2+2=4. Then, because division and multiplication are a tie in terms of which you do next, the left to right comes into play. So you divide 8 by 2 to get 4. Then you multiply by the 4 in the parentheses.

Turns out this isn't just one of those wonky wonders. Two different calculators came up with two different answers -- 1 and 16. Whatever team programmed the Casio followed the PEMDAS rule, but didn't know or didn't remember that the basic operations tie. That team gave multiplication the priority.

Or is the math professor wrong?

The Twitterverse is split. "It's 16," Tweeted @gcfssea. "omg, the replies [are] embarrassing." " 1. The amount of people saying 16 need to retake math," countered@JungKookQueen97.

Our money's with Strogatz. Let's just hope this gets sorted out before it ends up costing us another centimeters or inches debacle.

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